Ketchup Spaghetti |

Ketchup Spaghetti

Course: Main Course
Cuisine: Japanese
Keyword: japanese napolitan, pasta
Prep Time: 10 minutes
Cook Time: 20 minutes
Total Time: 30 minutes
Servings: 2
Author: Nami
Need a family meal that can be ready in 30 minutes? Try this Japanese ketchup spaghetti recipe with bell pepper, mushrooms, garlic, and sausage.


  • 7 oz spaghetti (7 oz = 200 g)
  • 1 clove garlic
  • ¼ - ½ onion
  • 6 sausages (I use Japanese “kurobuta” (black pork) sausages) or 2 Italian sausages)
  • 1 bell pepper
  • 4-6 mushrooms
  • 2 Tbsp extra virgin olive oil
  • 2 Tbsp milk
  • 2 Tbsp Parmesan cheese (freshly ground)


  • 4 Tbsp Ketchup
  • 1 tsp Worcestershire sauce
  • ¼ tsp sugar (optional)
  • 1-3 Tbsp reserved pasta water
  • salt (kosher or sea salt; use half if using table salt)
  • Freshly ground black pepper


  1. Gather all the ingredients.

    Ketchup Spaghetti Ingredietns
  2. Bring a large pot of salted water to boil. Cook the pasta according to the package directions.
    Ketchup Spaghetti 1
  3. Meanwhile, mince the garlic clove and slice onion, sausages, bell pepper and mushrooms.
    Ketchup Spaghetti 2
  4. In a large skillet or sauté pan, heat olive oil over medium heat. Add the garlic and sauté for 1 minute, just until golden and fragrant.
    Ketchup Spaghetti 3
  5. Add the onions to the pan and sauté for 2-3 minutes.
    Ketchup Spaghetti 4
  6. When the onions are wilted, add the sausages and sauté for 1 minute.
    Ketchup Spaghetti 5
  7. Add the bell peppers and mushrooms and sauté until everything is cooked.
    Ketchup Spaghetti 6
  8. Add the Sauce ingredients: Ketchup, Worcestershire sauce, and sugar (optional). When the sauce thickens, add the pasta cooking water. Season with salt and pepper to taste.
    Ketchup Spaghetti 7
  9. As soon as the pasta is cooked and drained, add to the pan and toss to combine using tongs.
    Ketchup Spaghetti 8
  10. Add the milk and Parmesan cheese and toss to combine. Serve immediately in warmed plates.
    Ketchup Spaghetti 9

Recipe Notes

Recipe by Namiko Chen of Just One Cookbook. All images and content on this site are copyright protected. Please do not use my images without my permission. If you’d like to share this recipe on your site, please re-write the recipe in your own words and link to this post as the original source. Thank you.