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A white bowl containing Japanese Spaghetti Napolitan with sliced ham, sliced onions and sliced green bell pepper with grated Parmesan on top of the spaghetti. There is a fork resting in the bowl and a bottle of ketchup and small bowl with Parmesan in the background.

Japanese Spaghetti Napolitan Recipe

Grace Stewart
This Japanese Spaghetti Napolitan Recipe is so easy and delicious! Also known as Ketchup Spaghetti, this dish is a wonderful example of Yoshoku, or Japanese Western food!
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Prep Time 10 minutes
Cook Time 15 minutes
Total Time 25 minutes
Course Main Course
Cuisine Japanese
Servings 5 people
Calories 482 kcal

Equipment

  • 1 large pot to cook the spaghetti
  • 1 large pan to fry the spaghetti and other ingredients together

Ingredients
  

  • 1 lb spaghetti cooked according to package directions
  • ½ cup reserved pasta water collect this water just prior to draining the pasta (you may not use all of this water but be sure to reserve it just in case)
  • 4 oz ham cut into thin strips; can sub other type of lunch meat
  • ½ onion select a large onion and cut ½ the onion into thin slices
  • ½ green bell pepper select a large green bell pepper and cut ½ the green bell pepper into thin slices
  • 2 tablespoon butter
  • 8 cloves garlic minced
  • 2 tablespoon olive oil

Ketchup Based Sauce

  • ⅓ cup ketchup
  • 2 tablespoon tomato paste
  • 1 ts Worcestershire sauce
  • ½ ts sugar
  • ¼ ts salt
  • ¼ ts pepper
  • 2 tablespoon water

Garnishes

  • Parmesan cheese as little or as much as you want!
  • Tabasco sauce for a lovely bit of heat!

Instructions
 

Prepare The Ketchup Sauce

  • Combine the sauce ingredients (ketchup, tomato paste, Worcestershire sauce, sugar, salt, pepper, and water) in a small bowl and mix well. Set the sauce aside.
    A ketchup based sauce in a white bowl. There is a spoon containing some of the sauce in the bowl.

Cook The Spaghetti

  • Bring a large pot of salted water to the boil, and cook your pasta according to the package directions. Collect ½ cup of pasta water just prior to draining the pasta, then drain the spaghetti and set aside.
    A large stock pot filled with boiling water and spaghetti with a red ½ cup measuring cup containing some of the pasta water poised above the stock pot. There is part of a red Dutch oven in the background.

Get The Veggies And Ham Ready

  • While you are cooking the pasta, heat up 2 tablespoon of olive oil in a large pan on medium heat. Add the onion and the minced garlic, and stir for 3 minutes until the onion is softened.
    Sliced onion and minced garlic in olive oil in a dutch oven.
  • Add the sliced green bell pepper and ham, and stir for around 2 minutes.
    A dutch oven containing sliced ham, sliced green bell pepper and onions with minced garlic.
  • Add the sauce to the ham and veggies, and stir to combine.
    A dutch oven containing sliced ham, sliced green bell pepper and onions with minced garlic. There is a ketchup based sauce poured over the vegetables and a blue turner utensil in the bottom right of the picture.

Now Add The Pasta, Reserved Pasta Water, and Butter!

  • Now add the pasta and mix everything together. Start adding reserved pasta water tablespoon by tablespoon until your pasta is nice and loose and doesn't stick together. You may or may not use all of the reserved pasta water. Then add the butter and mix it in, allowing it to melt. Taste and adjust seasoning to your liking.
    Japanese spaghetti with ketchup, slices of green bell pepper and onions in a dutch oven with a dab of butter and black pepper. There is a blue spaghetti server resting on the pasta.

Enjoy!

  • Garnish with Parmesan cheese and sprinkle some Tabasco and enjoy!
    A white bowl containing Japanese Spaghetti Napolitan with sliced ham, sliced onions and sliced green bell pepper with grated Parmesan on top of the spaghetti. There is a fork resting in the bowl and a bottle of ketchup and small bowl with Parmesan in the background.

Notes

The nutrition information doesn't include Parmesan cheese or Tabasco.
Feel free to sub other types of luncheon meat for ham if you like.
Itadakimasu!  (Bon Appetit!)

Nutrition

Calories: 482kcalCarbohydrates: 77gProtein: 18gFat: 11gSaturated Fat: 3gPolyunsaturated Fat: 2gMonounsaturated Fat: 6gCholesterol: 15mgSodium: 598mgPotassium: 444mgFiber: 4gSugar: 8gVitamin A: 235IUVitamin C: 14mgCalcium: 45mgIron: 2mg
Keyword ketchup spaghetti, napolitan, spaghetti, yoshoku
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