Ketchup in spaghetti?! You hear it right. The idea of spaghetti with ketchup sauce may make any Italian cringe. However, Japanese Ketchup Spaghetti, or what we call Spaghetti Napolitan (スパゲッティーナポリタン), has been a popular menu at cafe restaurants (Kissaten) since the 1950s. This comforting pasta dish always brings a nostalgic memory to many Japanese who grew up eating it.
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!
What is Napolitan?
Napolitan is tomato ketchup-based, Japanese-style pasta that consists of spaghetti noodles, onions, green bell peppers, button mushrooms, and Japanese sausages. There are a few variations where we replace the sausages with bacon or ham. However, in general, it all has a standard sunny look of appetizing orange.
Phonetically, the Japanese language doesn’t distinguish R and L as separate sounds. For that reason, it uses the same katakana characters to represent R and L sounds of Western alphabets. So we write it as either Napolitan or Naporitan. While the spelling “Naporitan” is derived from romanji (the romanization of Japanese), the spelling “Napolitan” takes the origin of the name (Napoli) into account.
The Origin of Napolitan
Napolitan was born in Yokohama after the war. The Hotel New Grand was requisitioned by GHQ, and the American officers billeted there ate their spaghetti boiled and tossed with ketchup. The hotel’s second head chef, Irie Shigetada, thought it could be better—he rebuilt it with fresh tomatoes, tomato paste, garlic, onion, and olive oil, and named it Spaghetti Napolitan after Naples.
The ketchup version started across town. Center Grill, a small yoshoku restaurant in Noge, opened in 1946 and used ketchup from the start, since fresh tomatoes were expensive and slow to cook down. Its founder had trained in Irie’s circle and took his advice after opening. That cheaper, faster version is the Napolitan that spread through Japan’s kissaten, and it’s the one in this recipe.
Ketchup as the Key Flavoring
Not surprisingly, Japanese cuisine has used ketchup in seasoning various dishes, as this all-star American condiment lends a depth of flavor with its sweet-tangy profile.
Therefore, you can find ketchup used in Japanese Curry, Omurice, Ebi Chili, and a pasta dish like Spaghetti Napolitan. It’s a great example of how open we are when it comes to adapting other cultural influences in improving our own cuisine.
Why You’ll Love This Pasta
The genius about Spaghetti Napolitan is that it utilizes most of the pantry staples in your kitchen. The common ingredients include onion, mushrooms, green bell peppers, and sausages (ham or bacon). It’s seasoned with ketchup and Parmesan cheese and served with Tabasco sauce.
It’s really flexible, too! For example, you can try bacon in place of sausage. Likewise, use peas in place of bell peppers. Top it with a fried egg if you’d like. But simplicity is good for this recipe. When you don’t have any of the ingredients in the recipe, you can throw in whatever happens to be in season or on-hand in your kitchen.
To make it vegetarian-friendly, leave out the meat and add more mushrooms. Mix it up with a different type of mushroom for texture and flavor.
It’s the kind of dinner that comes together faster than takeout, with whatever the fridge has in it. That’s why it stayed in our rotation for years.
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 the pasta cooking water – The starch in it acts as a binder and holds the emulsion together, so the sauce thickens without the butter separating out.
- 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 true kissaten texture, cook the pasta a day ahead – Boil the spaghetti, drain it, toss it with a little oil so it doesn’t clump, and refrigerate overnight. The strands absorb water all the way through, so the next day the sauce soaks into them instead of sitting on the surface.
It cannot be easier to put this Spaghetti Napolitan together! For a fancy yet effortless weeknight dinner, serve it with a green salad and wine. Enjoy!
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Napolitan (Japanese Ketchup Spaghetti)
Ingredients
For the Sauce Ingredients
- 5 oz sausages (4–6 pieces; see Notes for substitute)
- 4 mushrooms (2.5 oz, 70 g)
- ¼–½ green bell pepper (2.5 oz, 70 g)
- ½ onion (3.5 oz, 100 g)
- 1 clove garlic
- ¼ tsp Diamond Crystal kosher salt
- ⅛ tsp freshly ground black pepper
- 1 Tbsp extra virgin olive oil
For the Seasonings
- ⅓ cup ketchup (use Kagome Tomato Ketchup for an authentic taste)
- 2 tsp Worcestershire sauce (I use Lea & Perrins)
- ½ Tbsp milk (optional)
- 1 tsp sugar (optional)
For the Pasta
- 7 oz spaghetti
- 1½ Tbsp Diamond Crystal kosher salt
- 1 Tbsp unsalted butter
- ¼ cup reserved pasta water (if needed)
For Serving
- 2 Tbsp Parmigiano-Reggiano or Parmesan cheese
Instructions
Before You Start
- Gather all the ingredients. Start boiling a large pot of water (I use a 4-QT heavy-bottomed pot).
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.
- Cut ½ onion into thin slices.
- Cut ¼–½ green bell pepper in half crosswise (if it's long), and cut into thin strips.
- Cut 4 mushrooms into thin slices.
- Cut 5 oz sausages diagonally into thin slices.
To Boil the Spaghetti
- Add 1½ Tbsp Diamond Crystal kosher 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. Don't drain the spaghetti when it's done—you'll need to reserve ¼ cup reserved pasta water shortly.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.
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 1 minute until fragrant.
- Add the onions and sauté for 2–3 minutes until wilted.
- Add the sausages and sauté for 1 minute.
- Add the bell peppers and mushrooms and sauté until tender.
- Season with ¼ tsp Diamond Crystal kosher salt and ⅛ tsp freshly ground black pepper.
- Push the ingredients to one side. Add the sauce mixture to the empty side of the pan. When it starts to bubble and thicken, about 30 seconds, mix it together with the sausages and vegetables.Nami's Tip: Cooking the ketchup on its own takes the sharp edge off and brings out the spices already in it—that mellow taste is what makes Napolitan taste like a kissaten made it.
- Scoop ¼ cup reserved 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 starch in this salty pasta water acts as a binder and holds the emulsion together, helping the sauce thicken without the fat and water separating.
- Mix to combine, and let the sauce simmer and reduce a bit. Nami's Tip: If the sauce tastes too acidic, stir in a little mirin or sugar here. The butter in the next step softens the acidity further and adds creaminess.
- 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.
To Serve
- Serve immediately on individual plates. Shave 2 Tbsp Parmigiano-Reggiano or Parmesan cheese over the pasta now or at the table.
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
- 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.
- Vegetarian. Leave out the sausage and add extra mushrooms. A mix of shiitake and button mushrooms gives more texture.
- 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
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Editor’s Note: This post was originally published on Apr 19, 2013. The post has been republished with updated content, new images, and a slightly-revised recipe on July 25, 2022.
