A plate of ketchup spaghetti with sausage, green peppers, onions, and mushrooms, topped with grated cheese, sits on a white dish with a fork on the side.

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Napolitan at a Glance

Napolitan (ナポリタン) is a classic yoshoku (Japanese-style Western dish), featuring spaghetti in a ketchup-based sauce. Its history is closely associated with Chef Shigetada Irie at Yokohama’s Hotel New Grand, who developed a tomato-sauce version after World War II. As the dish spread to kissaten (cafe restaurants), cooks swapped in shelf-stable ketchup to create the version we know today.

Why You’ll Love It

  • Ready in 20 minutes – Ideal for a quick lunch or weeknight dinner using common pantry staples.
  • More than just ketchup – Cooked down with Worcestershire sauce and butter, the sauce turns sweet, tangy, and savory.
  • A taste of retro Japan – Recreate the nostalgic napolitan pasta served at Japan’s kissaten cafes in your own kitchen.
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What readers say
“A lovely, well rounded dish and so fast. Honestly I wouldn’t have thought this contains ketchup if I had not cooked it myself.”

SYLKE K

My Recipe Story

Napolitan is the pasta my son asked for by name. Whenever I asked what he wanted for lunch, this was the answer. My kids like the bell peppers cooked soft rather than crunchy, so that’s how I make it at home — one of those small adjustments every family lands on. Every kissaten in Japan has its own version too.

If you love Japanese-style pasta, try my Ume Shiso Pasta, Miso Butter Pasta with Tuna and Cabbage, and Creamy Mushroom and Bacon Pasta next!

A plate of Napolitan (ketchup spaghetti with tomato sauce), sliced sausage, green bell peppers, and mushrooms, topped with grated cheese. A fork rests on the plate next to a drink, napkin, and cheese grater.

Key Ingredients

You’ll need spaghetti, sausage, vegetables, mushrooms, a ketchup-based sauce, garlic, milk, sugar, extra virgin olive oil, butter, and Parmesan cheese for serving.

  • Spaghetti – I recommend 1.6–1.9 mm spaghetti for a satisfying texture that holds up well when tossed with the sauce.
  • Ketchup – This gives Napolitan its signature sweet, tangy flavor. I recommend Kagome Tomato Ketchup for an authentic Japanese taste.
  • Worcestershire sauce – Adds savory depth to the ketchup sauce. Tonkatsu sauce or soy sauce works as a substitute.
  • Sausage – Japanese kurobuta or arabiki sausages are my favorites. Other sausages, ham or bacon work, too.
  • Mushrooms – Add savory flavor. Use button mushrooms, cremini, or what you have available.
  • Green bell pepper and onion – Classic vegetables that bring color and sweetness.

Find the printable recipe with measurements below.

Jump to Recipe

How to Make Napolitan

  1. Prep the ingredients. Thinly slice the onion, bell pepper, mushrooms, and sausages. Mix the ketchup, Worcestershire sauce, and optional milk and sugar in a bowl.
  2. Cook the spaghetti. Boil in salted water for the full package time, or slightly longer if you prefer a softer texture. Reserve ¼ cup of cooking water before draining.
  3. Sauté the toppings. Cook crushed garlic in olive oil until fragrant. Add the onion, followed by the sausages, bell pepper, and mushrooms. Cook until tender and season with salt and pepper.
  4. Cook the sauce. Push the toppings aside and pour the sauce into the empty side of the pan. Let it bubble and thicken, then mix everything together. Add a splash of pasta water if needed.
  5. Toss and serve. Add the spaghetti and butter, then toss to coat. Serve right away with grated Parmesan cheese.
A person slices sausage links into thin pieces on a wooden cutting board with a large kitchen knife, preparing the ingredients for ketchup spaghetti.
A hand uses tongs to stir uncooked ketchup spaghetti in a large pot of boiling water on a stove.
Sliced sausage, mushrooms, green bell peppers, and onions are being stir-fried in a large pan on a stovetop to create a delicious base for ketchup spaghetti. A wooden spatula rests on the side of the pan.
Sliced sausages, onions, mushrooms, and green peppers cooking in a skillet evoke the classic flavors of ketchup spaghetti, while tomato sauce is being poured in from a measuring cup on the right side.
A plate of ketchup spaghetti with sliced sausages, bell peppers, mushrooms, and tomato sauce is served with a fork on a light-colored, ridged plate.
Namiko Hirasawa Chen

Nami’s Recipe Tips

  • Have the sauce ready before the pasta is – The spaghetti keeps softening the moment it leaves the water, so the sauce should be waiting for it, not the other way around.
  • Ketchup brands taste different – I use this organic ketchup, but any good one works. For an authentic Japanese flavor, look for Kagome Tomato Ketchup at a Japanese grocery store.
  • Reserve some pasta cooking water – The starchy water helps the sauce come together and cling to the spaghetti. Add a splash as needed to loosen the sauce while tossing.
  • Don’t cook the spaghetti al dente – Napolitan is meant to be softer than Italian pasta. Cook it for the full package time, or a minute past.
  • Cook the vegetables to your family’s taste – Keep the bell peppers crunchy, or slice them thin and cook them soft if that’s what your family prefers. Take the onion a little further than you think, short of caramelizing, to draw out the sweetness.
  • Finish with a tablespoon of butter – It rounds off the ketchup’s sharpness and gives the sauce its gloss. Don’t skip it.
  • For a kissaten-style texture, prep the pasta ahead – Cook the spaghetti, drain, toss with a little oil, and refrigerate overnight. As the pasta rests, moisture redistributes through the strands, giving them the softer, more uniform texture associated with café-style Napolitan.

Storage and Reheating Tips

To store: This dish tastes best fresh, so I don’t recommend making extra. If you have leftovers, refrigerate them in an airtight container for up to 3 days or freeze for up to 1 month.

To reheat: Warm the pasta in a frying pan over medium heat, adding a splash of water to loosen the sauce.

A plate of Napolitan (ketchup spaghetti with tomato sauce) with sliced sausage, green bell peppers, onions, and a tangy tomato-based sauce, served with a fork. A glass of iced drink and another plate are visible in the background.
A plate of ketchup spaghetti with sausage, green peppers, onions, and tomato sauce, with a fork lifting a twirl of pasta.

Variations

Feel free to mix and match based on what you have in the fridge or pantry.

  • Vegetarian. Omit the sausage, use vegetarian Worcestershire sauce, and add extra mushrooms.
  • Mix up the mushrooms. Use shiitake, cremini, or a blend in place of button mushrooms for a deeper, earthier flavor.
  • Add peas. Swap in ½ cup of green peas or sugar snap peas for the bell pepper, or add them alongside.
  • Top with a fried egg. Slide a sunny-side-up egg over each plate. The runny yolk makes the sauce even richer.
  • Add heat. Stir dried red chili flakes into the pasta, or set out hot sauce at the table.

What to Serve with Napolitan

Round out the meal with a few sides:

  • Corn Potage – Warm, silky Japanese corn soup that rounds out a cozy weeknight dinner.
  • Japanese Potato Salad – Its creamy, tangy bite balances the sweet ketchup sauce for a satisfying plate.
  • Green Salad with Carrot Ginger Dressing – A crisp, zingy salad that cuts through the richness of the pasta.
  • Ebi Fry – Crisp, panko-breaded fried shrimp turns the meal into a classic yoshoku plate.
Black bowls containing Japanese corn potage.
A bowl of Japanese potato salad with visible chunks of potato, ham, boiled egg, cucumber, and carrot, placed on a rustic plate beside wooden utensils and a beaded decoration.
White plates of fresh green salad with lettuce, cucumbers, radishes, and cherry tomatoes, topped with vibrant orange carrot ginger dressing and served with a gold fork on a marble surface.
A white plate containing Ebi Fry served with tartar sauce.

FAQ

Why is it called Napolitan?

The name nods to Naples (Napoli), Italy, though the dish was created in Japan. In Japanese, R and L share one sound, so you’ll also see it spelled Naporitan.

What sausage works best?

Kurobuta or arabiki Japanese sausages give the most authentic taste. Ham, bacon, or wieners all work if that’s what you have on hand.

How is Naolitan different from Italian spaghetti dishes?

Napolitan is a Japanese creation known for its ketchup-based sauce and softer noodles. Its sweet, tangy flavor gives it a character of its own.

Is Napolitan spicy?

No, this Napolitan pasta is mild and slightly sweet, so it’s kid friendly. Cafes in Japan serve it with Tabasco sauce and Parmesan on the side, so you can adjust the heat.

I’d love to hear how yours turned out! 💛 Please leave a star rating and comment below to share your experience. Your feedback not only supports Just One Cookbook but also helps other home cooks discover recipes they can trust.

Napolitan (Japanese Ketchup Spaghetti)

4.71 from 154 votes
by Namiko Hirasawa Chen
A plate of ketchup spaghetti with tomato sauce, sliced sausage, green bell peppers, and mushrooms, topped with grated cheese. A fork rests on the plate next to a drink, napkin, and cheese grater.
Napolitan is a nostalgic cafe classic ready in about 20 minutes. This recipe coats spaghetti in a sweet-savory ketchup sauce with sausage, onion, mushrooms, and bell pepper. Finish with butter for richness, and serve with a green salad.
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Prep: 10 minutes
Cook: 10 minutes
Total: 20 minutes

Ingredients 
 

Servings: 2

For the Sausage and Vegetables

For the Sauce Ingredients

For the Pasta

For Serving

  • 2 Tbsp Parmigiano-Reggiano or Parmesan cheese

Instructions

Before You Start

To Prepare the Ingredients

  • Add ⅓ cup ketchup, 2 tsp Worcestershire sauce, ½ Tbsp milk (optional), and 1 tsp sugar (optional) to a small bowl. Mix together and set aside.
    Nami's Tip: Both are optional, but the milk makes the sauce creamier and the sugar gives Napolitan its characteristic sweetness.
    A hand pours sugar into a glass bowl containing napolitan sauce and milk, then uses a blue spatula to stir the ingredients together.
  • Thinly slice ½ yellow onion and 4 mushrooms. Cut 5 oz sausages diagonally into thin slices.
    A three-part image showing hands slicing an onion, a mushroom, and cooked sausage links on a wooden cutting board to prepare ingredients for Napolitan.
  • Cut ¼–½ green bell pepper in half crosswise (if it's long), and cut into thin strips.
    Hands using a chef’s knife to slice a green bell pepper on a wooden cutting board for a napolitan dish.

To Boil the Spaghetti

  • Add 1½ Tbsp Diamond Crystal kosher salt (use half the amount or the same weight for table salt) and 7 oz spaghetti to the boiling water. Stir to keep the noodles from sticking to each other. Cook according to the package directions.
    Make the sauce while it cooks so both finish together. Before draining, reserve ¼ cup pasta water. Drain the spaghetti when cooked and add it to the sauce promptly.
    Nami's Tip: Napolitan isn't served al dente. Cook the spaghetti for the full package time or a minute past it—the softer texture is part of the dish.
    A hand adds a spoonful of salt to boiling water in a pot, followed by a hand using tongs to submerge long noodles for a Napolitan pasta dish.

To Cook the Sauce

  • Heat a large frying pan over medium heat. Add 1 Tbsp extra virgin olive oil and distribute it evenly.
    Crush 1 clove garlic with a garlic press and add it to the pan. Sauté for 30 seconds until fragrant.
    Add the onions and sauté for 2–3 minutes until tender.
    A three-part sequence showing oil being poured into a pan for napolitan, followed by minced garlic being stirred, and then sliced onions being added to the pan.
  • Add the sausages and sauté for 1 minute, then add the bell peppers and mushrooms.
    A two-panel image showing sliced sausage being added to a pan with sautéed onions for napolitan, followed by sliced green peppers and mushrooms added to the mixture.
  • Cook, stirring, until the sausages are heated through and the vegetables are tender. Season with ¼ tsp Diamond Crystal kosher salt (use half the amount or the same weight for table salt) and ⅛ tsp freshly ground black pepper.
    A split-view image showing sliced sausage, mushrooms, green peppers, and onions for a Napolitan stir-fry being cooked in a wok, with hands adding salt and pepper from small glass bowls.
  • Push the ingredients to one side and add the sauce mixture to the empty side of the pan. Let it bubble and thicken for about 30 seconds, then mix with the sausages and vegetables.
    Nami’s Tip: Cooking the sauce before mixing it with the other ingredients mellows the ketchup’s tanginess and brings out its flavor for that classic kissaten taste.
    A two-part image showing tomato sauce being poured into a skillet of sautéed sausage, onions, mushrooms, and bell peppers for Napolitan, then being stirred together.
  • Scoop ¼ cup pasta water from the pot. If the sauce looks too thick, stir in 1–2 Tbsp of pasta water to loosen it. Add more if needed.
    Nami's Tip: The starchy cooking water helps the sauce come together and coat the spaghetti. Add a splash as needed to loosen it.
    A split image showing water being poured into a pot of boiling liquid on the left, and broth being poured into a pan of sautéing sliced sausages and vegetables for a napolitan dish on the right.
  • Mix to combine, and let the sauce simmer and reduce a bit.
    Once the spaghetti is done, drain it and add it to the pan with the sauce. Add 1 Tbsp unsalted butter and toss with tongs until the pasta is evenly coated.
    Nami's Tip: If the sauce tastes too tangy, add a little more sugar to taste. The butter added next brings richness and rounds out the flavor.
    A two-part image showing sliced sausages, peppers, and onions sautéing in a pan, then being tossed with cooked spaghetti and a pat of butter to create a classic Napolitan.

To Serve

  • Serve immediately on individual plates. Grate 2 Tbsp Parmigiano-Reggiano or Parmesan cheese over the pasta now or at the table.
    Two photos of Napolitan pasta with sliced sausages and green peppers on a white fluted plate, with the left image showing metal tongs tossing the noodles.

To Store

  • Napolitan is at its best straight out of the pan, so it's worth cooking only what you'll eat. If you do have leftovers, store them in an airtight container in the refrigerator for up to 3 days, or in the freezer for up to a month.

Notes

Ingredients
  • Spaghetti: Thicker strands, around 1.6–1.9 mm, suit Napolitan best. They hold the sauce and keep their chew through the stir-frying.
  • Japanese sausages: Kurobuta or arabiki sausages are sold at Japanese markets. Another type of sausage, ham, or bacon works too.
  • Worcestershire sauce: Tonkatsu sauce or soy sauce works as a substitute.
Variations
  • Vegetarian. Omit the sausage, use vegetarian Worcestershire sauce, and add extra mushrooms. 
  • Add peas. Swap in ½ cup of green peas or sugar snap peas for the bell pepper, or add them alongside.
  • Top with a fried egg. Slide a sunny-side-up egg over each plate. The runny yolk makes the sauce even richer.
  • Mix up the mushrooms. Use shiitake, cremini, or a blend in place of button mushrooms for a deeper, earthier flavor.
  • Add heat. Stir dried red chili flakes into the pasta, or set out hot sauce at the table.

Nutrition

Calories: 684kcal, Carbohydrates: 93g, Protein: 22g, Fat: 25g, Saturated Fat: 6g, Cholesterol: 23mg, Sodium: 673mg, Potassium: 776mg, Fiber: 6g, Sugar: 15g, Vitamin A: 445IU, Vitamin C: 54mg, Calcium: 126mg, Iron: 3mg

The nutrition facts shown are generated by an online calculator and are estimates only. Please consult a professional nutritionist for specific dietary needs.

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Editor’s Note: This post was originally published on April 19, 2013. It was republished with new images and a slightly revised recipe on July 25, 2022, and updated with more helpful cooking tips on October 25, 2026.