Name: How To Make Napolitan (Japanese Ketchup Spaghetti Recipe)
Prep time: 10 min
Cook time: 20 min
Total time: 30 min
Yield: 2
Cuisine: Japanese
Ingredients: 200g Spaghetti; 2 tsp Salt; 1 Tbsp Olive Oil; 1 Clove Garlic; 80g Onion; 80g Green Bell Pepper; 80g Mushrooms; 140g Sausage or Hotdog; 8 Tbsp Ketchup (for the sauce); 6 Tbsp Milk (for the sauce); 1 Tbsp Worcestershire sauce (for the sauce); ½ tsp Salt (for the sauce); 60ml Reserved Pasta Water (for the sauce); Black Pepper, to taste; 15g Parmesan cheese (optional); Parsley, to taste (optional)

How To Make Napolitan (Japanese Ketchup Spaghetti Recipe)

MainKetchupPastaSpaghettiNoodleWeeknight dinner ideaUnder 30 minsEasy

Napolitan, also known as Napolitan spaghetti, is a uniquely Japanese pasta dish that puts a playful twist on Western-style cooking. Despite its Italian-sounding name, this dish has no direct connection to Naples or traditional Italian cuisine. Instead, it is a beloved example of yōshoku, Japanese interpretations of Western food.

Napolitan spaghetti is typically made with spaghetti noodles stir-fried with familiar ingredients such as onions, green bell peppers, mushrooms, and sausage or bacon. What truly sets it apart is the seasoning. Instead of tomato sauce, the dish is flavored with ketchup, giving it a sweet, tangy taste that is both comforting and addictive. A sprinkle of grated Parmesan cheese and a dash of black pepper are often added at the end for extra depth.

This dish is commonly served in Japanese cafes, family restaurants, and home kitchens. It is casual, approachable, and deeply nostalgic for many people in Japan. For some, it brings back memories of childhood lunches or simple meals enjoyed with family.

Napolitan is also popular because it is easy to make. No special techniques or equipment are needed. The ingredients are affordable, and the cooking process is straightforward. Everything comes together in one pan, making it perfect for busy weeknights.

In this recipe, we share the most classic version using sausages, onions, bell peppers, and mushrooms. However, Napolitan is very flexible. You can make it spicy, add more vegetables, or top it with a sunny-side-up egg. Simple yet satisfying, Napolitan spaghetti is comfort food with a fun Japanese twist that never goes out of style.

If you enjoyed this Napolitan spaghetti recipe, why not explore more Japanese-style pasta dishes? Try something creamy and bold with this Mentaiko Pasta (Spicy Cod Roe Butter Spaghetti), a popular Japanese favorite with rich umami flavor. Or, for a unique fusion twist, check out this Udon Carbonara Recipe, which combines chewy udon noodles with a creamy, Japanese-Italian style sauce. Both recipes are easy to make at home and perfect for anyone curious about Japan’s creative take on classic pasta dishes.

Overview

Prep time: 10 minsCook time: 20 minsTotal time: 30 mins

Total servings: 2

Difficulty: Easy

Main Ingredients

Spaghetti

200 g

Salt

2 tsp

Olive oil

1 tbsp

Garlic

1 clove

Onion

80 g

Green bell pepper

80 g

Mushrooms

80 g

Sausage or hotdog

140 g

For the Sauce

Ketchup

8 tbsp

Kagome Low Sodium Japanese Organic Ketchup 300g

Milk

6 tbsp

Worcestershire sauce

1 tbsp

Bull-Dog Sauce Japanese Worcestershire Sauce 300ml

Salt

1/2 tsp

[ingredient-product3]

Reserved pasta water

60 ml

Black pepper

to taste

Takusei Black Pepper & Japanese Garlic Seasoning Powder Steak Rub 25g

Optional

Parmesan cheese

15 g

Parsley

to taste

Instructions

1) Gathering the Ingredients

Gather all of the ingredients together.

2) Slicing the Vegetables & Sausage

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Prepare the veggies and protein for napolitan by finely mincing one clove of garlic and thinly slicing the onion, green bell pepper, and mushrooms. Then, thinly slice the sausages.

If you want to garnish your Napolitan with grated parmesan cheese and/or parsley, this would be a good point to prepare those as well.

Tip: Make sure the onion and green bell pepper are sliced to about the same thickness.

Expert's Tip

The most important ingredient of this dish is ketchup, and the Kagome Low Sodium Japanese Organic Ketchup is the perfect fit for this recipe. You might think that all ketchup is the same, but trust us, they're not! The sweetness and sourness of ketchup can vary greatly depending on the brand. We're pretty sure that if you use this ketchup in your Napolitan recipe, your dish will turn out amazing.

3) Preparing the Ketchup Sauce

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Combine ketchup, worcestershire sauce, milk, and salt in a small pot. Mix them well to combine and set aside.

4) Cooking the Spaghetti

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Bring 2 liters of water to a boil in a large pot, and add 2 teaspoons of salt. Cook the spaghetti according to your package's instructions.

Note: Save 60ml of the cooking water for the ketchup sauce.

5) Cooking the Ketchup Sauce

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Heat the ketchup sauce that you mixed over medium heat. Add 60ml of the cooking water from the boiled spaghetti. Simmer the sauce for a few minutes until it thickens.

6) Cooking the Vegetables and Sausage

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In a separate pan, heat 2 teaspoons of olive oil and add in the chopped clove of garlic. Once it becomes fragrant, add in the onion and stir-fry for 1 minute, then add the sausage and sauté until slightly browned. Then add in the green bell pepper and mushrooms, and sauté for a couple more minutes, until cooked.

7) Adding the Ketchup Sauce and the Pasta

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At this point, your spaghetti should be fully cooked. Drain it from the water and set it aside in a colander until you're ready to use it.

Once the vegetables and sausages are cooked to your liking, add in the prepared ketchup sauce and stir well to combine. Then, add in the cooked pasta and toss everything together using tongs. Season to taste with black pepper.

8) Serving the Napolitan

Divide the spaghetti onto serving plates. Garnish with grated Parmesan cheese and sprinkle some parsley on top or side for added flavor and presentation. Enjoy!

Mana Sobral

Mana is a mother of two who is currently based in Toronto, Canada. While she has called Toronto her home for the past 7 years, she is originally from Wakayama. She holds a bachelor’s degree in Nutrition and gained practical experience working as a dietician in Japan. She is absolutely obsessed with sharing her love for Japanese cuisine. She loves the seasonality of vegetables in Japan and the creativity of plating dishes. She loves writing Japanese recipes and sharing them with people around the world. She prefers to keep her writing style simple and fun, so that everyone, including people who are not particularly keen on reading, can enjoy her articles. In her free time, she loves baking desserts and Japanese breads. She also enjoys participating in Muay Thai classes.

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