Need a family meal ready in under 20 minutes? Try this quick and easy Japanese Ketchup Spaghetti, known as Napolitan. Home cooks all across Japan prepare this simple recipe that elevates pantry staples with fresh ingredients like sausages, mushrooms, onion, and bell pepper. It’s a savory and satisfying dish!
Ketchup in spaghetti?! You hear it right. The idea of spaghetti with ketchup sauce may make any Italians 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 50s. This comforting pasta dish always brings a nostalgic memory to many Japanese who grew up eating it.
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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 sausages are replaced with bacon or ham, but 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 it can be written as Napolitan or Naporitan: The spelling “Naporitan” is derived from romanji (the romanization of Japanese), while the spelling “Napolitan” takes the origin of the name (Napoli) into account.
There are a few theories of how Napolitan originated. The strongest theory is that it originated in Yokohama during the postwar era.
Around the 1950s, the head chef at the New Grand Hotel in Yokohama created this recipe after being inspired by the spaghetti and tomato sauce dish served to the American military. Since tomato sauce was a rare ingredient at that time, ketchup was used as a substitute for pasta. He then named it “Spaghetti Napolitan”, or Napoli, after Naples, Italy.
Around the same time, Japan started to open itself to the world and new ideas from the west were considered fashionable. These newly westernized dishes like Spaghetti Meat Sauce and Spaghetti Napolitan received excellent responses that they became mainstays in the cafes and Japanese home kitchens. To this day, the two dishes are still two of the most popular pasta dishes among Yoshoku (western-influenced food, 洋食) in Japan.
Ketchup As The Key Flavoring
Japanese cuisine has been using ketchup in flavoring various dishes as this all-star American condiment lends a deep depth with its sweet-tangy profile.
You can find ketchup being 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! Try bacon in place of sausage. Use peas in place of bell pepper. Top it with a fried egg if you’d like. But simple 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 mushrooms for texture and flavor.
This dish is really easy to make and the flavor is kids-friendly. It makes an ideal meal for a quick dinner if you have a family with young children. I remember my son used to request this Ketchup Spaghetti when I asked what kind of pasta he would like for lunch.
Spaghetti Napolitan Tips
- Timing is key for a smooth workflow. Get your prep work done while you boil the water to cook the spaghetti. You should have the cooked ingredients and sauce ready by the time the spaghetti is done cooking. Then toss everything together and serve!
- The taste of ketchup slightly varies depending on the brand. I usually use this organic ketchup (No GMO ingredients, no high-fructose corn syrup) but a similar one would work great. Napolitan does have a slightly sweet taste to it, but feel free to omit the sugar as listed in the recipe. For the authentic flavor, get a bottle of Kagome Tomato Ketchup from the Japanese grocery store. It is the classic Japanese ketchup to make Omurice and Napolitan.
- Always reserve the pasta cooking water. Set aside ¼ cup (or more depending on the serving portion) of the pasta cooking water. The starch in this salty pasta water acts as a binder and creates an emulsion when it is added to the sauce that contains fat like butter or oil.
- Don’t overcook the spaghetti as you will continue to cook a bit more in the frying pan.
- Consider textures. In my opinion, this pasta dish tastes best with various textures. For veggies such as bell peppers or fresh peas or sugar snap pea, I’d keep them on the crunchy side. However, my kids do not like raw or undercooked bell peppers so they always ask them to be as thin and wilted as possible. I personally like to cook the onion a bit more (no need to caramelize) to get the sweet flavor out of it.
- Just a tablespoon of butter at the end adds umami and creaminess to the dish. So don’t skip it!
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!
Tableware from Musubi Kiln
I’ve partnered with a great ceramic online shop from Japan called Musubi Kiln. You will get 10% off with a coupon code JUSTONECOOKBOOK for your purchase. In this post, I’ve used:
Other Japanese-Style Pasta Recipes
- Miso Butter Pasta with Tuna and Cabbage
- Creamy Mushroom and Bacon Pasta
- Ume Shiso Pasta
- Japanese-style Pasta with Shrimp and Broccolini
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Napolitan (Japanese Ketchup Spaghetti)
- ½ onion (3.5 oz or 100 g for 2 servings)
- ¼-½ green bell pepper (2.5 oz or 70 g for 2 servings)
- 4 mushrooms (2.5 oz or 70 g for 2 servings)
- 5 oz sausages (I use 4-6 kurobuta or arabiki sausages from a Japanese grocery store, but you can use another type of sausage, ham, bacon, etc.)
- 1 Tbsp extra virgin olive oil
- 1 clove garlic
- ¼ tsp Diamond Crystal kosher salt
- ⅛ tsp freshly ground black pepper
For the Sauce
- ⅓ cup ketchup (for the authentic flavor, get a bottle of Kagome Tomato Ketchup from the Japanese grocery store)
- ½ Tbsp milk (optional; add if you want a creamier taste)
- 2 tsp Worcestershire sauce
- 1 tsp sugar (optional; for an authentic Japanese taste)
- ¼ cup reserved pasta water (you may not need it; please check your sauce and add gradually)
For the Pasta
- 7 oz spaghetti
- 1½ Tbsp Diamond Crystal kosher salt
- 1 Tbsp unsalted butter
- 2 Tbsp Parmigiano-Reggiano or Parmesan cheese
- Gather all the ingredients. Start boiling a large pot of water (I use a 4 QT pot).
To Prepare the Ingredients
- In a small bowl, combine all the sauce ingredients and mix them together.
- Cut the onion into thin slices.
- Cut the green bell pepper in half lengthwise (if it's long), and then cut into thin strips.
- Cut the mushrooms into thin slices.
- Cut the sausages diagonally into thin slices.
To Boil the Spaghetti
- Once the water is boiling, add the salt and spaghetti. Stir to make sure the noodles don't stick to each other. Cook the spaghetti according to the package directions. Toward the end of cooking, you will reserve some pasta cooking water.While the pasta is cooking, prepare the sauce.
To Cook the Sauce
- Heat a large frying pan over medium heat. When it's hot, add the oil and distribute it evenly. Add the crushed garlic (I use this garlic press) and sauté for 1 minute, just until golden and fragrant.
- Add the onions to the pan and sauté for 2-3 minutes.
- When the onions are wilted, add the sausages and sauté for 1 minute.
- Add the bell peppers and mushrooms and sauté until everything is cooked.
- Season with the salt and pepper.
- Push the ingredients to one side and add the sauce mixture to the empty side of the pan. When the sauce starts to bubble and thicken, mix it together with the sausages and vegetables.
- Now, scoop out some of the starchy cooking water from the pasta pot, about ¼ cup for 2 servings. Remember, you may not need the reserved pasta cooking water that you saved. Add it to the pasta sauce only if it needs to loosen up. At times, I do not use it at all or use 1-2 Tbsp. Check the consistency of the sauce, and gradually add reserved pasta water, stirring well, until the sauce is the consistency you like.
- Mix it all together and let the sauce simmer and reduce a bit.
- By now, the spaghetti should be done cooking. Drain it well in a colander and add it to the pan with the sauce. Add the butter and toss to combine using tongs, making sure the sauce coats the pasta evenly.
- Serve the Napolitan immediately on individual plates. Shave the Parmesan cheese over the pasta now or at the table.
- You can keep the leftovers in an airtight container and store them in the refrigerator for 3 days or in the freezer for a month.
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.