When you want to turn simple ingredients like sausage, onion, and bell pepper into something a little different, Japanese Napolitan spaghetti is an easy pasta dish to make at home.
This Japanese Napolitan spaghetti recipe uses pasta cooked in salted water for 9 minutes, then combines it with browned sausage and vegetables in a sauce made with 8 tbsp ketchup, milk, and Worcestershire sauce. The key is to cook the ketchup sauce over medium heat long enough to evaporate excess moisture and mellow its sharp acidity. The finished pasta is coated in a rich sweet-and-tangy sauce, with savory sausage, tender onion, and the fresh bite of green bell pepper in every forkful.
⏱️ Cooking Time: About 25 minutes
🍳 Difficulty: ★★☆☆☆
✓ Ingredients (2 Servings)
🥣 Main Ingredients
- 200 g (7 oz) pasta
- 1/2 onion
- 1 green bell pepper
- 4 sausages, 60 g (2.1 oz)
🧂 Seasonings & Sauce
- 1.5 L (50.7 fl oz) water, for cooking the pasta
- 1 tbsp salt, for cooking the pasta
- Cooking oil
- 8 tbsp ketchup, 140 g (4.9 oz)
- 6 tbsp milk, 90 ml (3 fl oz)
- 1 tbsp Worcestershire sauce, 15 ml (0.5 fl oz)
(Measurement guide: 1 tbsp = 15 ml, 1 tsp = 5 ml, 1 Korean paper cup = 180 ml / 6.1 fl oz)
✓ How to Make Japanese Napolitan Spaghetti
- Prepare the pasta water: Bring 1.5 L (50.7 fl oz) water to a boil in a pot and add 1 tbsp salt.
- Cook the pasta: Add 200 g (7 oz) pasta to the boiling salted water and cook over high heat for 9 minutes. Follow the cooking time indicated on the pasta package if it differs.
- Slice the onion: While the pasta cooks, slice 1/2 onion into strips about 5 mm thick. Avoid slicing it too thin so it keeps some texture after cooking.
- Prepare the bell pepper and sausage: Cut 1 green bell pepper in half and remove the stem and seeds. Slice it into bite-size strips. Slice 4 sausages, 60 g (2.1 oz), diagonally.
- Drain the pasta: After 9 minutes, drain the cooked pasta in a colander.
- Brown the sausage: Add cooking oil to a skillet and cook the sausage over medium heat first. Let the surfaces brown well to develop more flavor.
- Sauté the vegetables: Add the onion and green bell pepper to the browned sausage and sauté together. Once everything is evenly cooked, transfer the sausage and vegetables from the skillet and set aside temporarily.
- Mix the Napolitan sauce: Turn off the heat. Add 8 tbsp ketchup, 140 g (4.9 oz), 6 tbsp milk, 90 ml (3 fl oz), and 1 tbsp Worcestershire sauce, 15 ml (0.5 fl oz), to the skillet. Mix until evenly combined.
- Cook the sauce: Turn the heat back on to medium and cook the sauce while stirring continuously. Continue until excess moisture from the ketchup evaporates, the sauce thickens, and the ketchup’s sharp acidity becomes milder.
- Return the sausage and vegetables: Add the cooked sausage, onion, and green bell pepper back to the sauce and mix evenly.
- Toss with the pasta: Add the cooked 200 g (7 oz) pasta and toss thoroughly until every strand is evenly coated with the ketchup sauce.
✓ Key Tip for Success
- Cook off enough moisture from the ketchup sauce: If you add the pasta immediately after mixing the ketchup, milk, and Worcestershire sauce, the sauce can remain thin and taste overly sharp. Cook it over medium heat while stirring until some of the moisture evaporates and the ketchup flavor becomes smoother before adding the other ingredients and pasta.
✓ Serving Tips
- Brown the sausage before adding the vegetables to develop a more savory, lightly roasted flavor on the surface.
- Do not slice the green bell pepper too thin if you want it to retain some of its characteristic bite after cooking.
- Toss the pasta thoroughly at the end so the Napolitan sauce evenly coats every strand.
✓ How to Choose Good Onions
- Outer skin: Choose onions with dry, papery outer skins that have a slight sheen and show no obvious cuts, disease spots, or mold.
- Firmness: Fresh onions should feel heavy and firm for their size, without soft areas that sink when pressed.
- Stem and sprouts: Look for onions with a thin, dry, tightly closed neck and no green sprouts.
Source: Rural Development Administration, Nongsaro – Characteristics and Nutritional Value of Onions
✓ Onion Nutrition per 100 g (3.5 oz)
| Nutrient | Amount per 100 g (3.5 oz) |
|---|---|
| Calories | 29.00 kcal |
| Carbohydrates | 6.52 g |
| Protein | 0.96 g |
| Fat | 0.17 g |
| Sodium | 2.00 mg |
Based on 100 g of raw onion. Actual nutrition values may vary depending on the variety, product, and cooking method.
Source: Ministry of Food and Drug Safety Food Nutrition Database – Onion, Raw
✓ Frequently Asked Questions (FAQ)
Q1. Why does my Napolitan sauce taste too sour?
If you do not cook off enough moisture from the ketchup sauce, the ketchup’s natural acidity can remain too strong. After mixing 8 tbsp ketchup, 6 tbsp milk, and 1 tbsp Worcestershire sauce, cook the sauce over medium heat while stirring until some of the moisture evaporates.
Instead of simply tossing ketchup directly with the noodles, cooking it with milk and Worcestershire sauce over medium heat gives the sauce a smoother flavor and helps it cling more richly to the pasta. When I made the recipe as written, the browned sausage, crisp green bell pepper, and sweet onion worked especially well with the sweet-and-tangy sauce, creating the familiar yet distinctive flavor of Japanese-style spaghetti.
If you want to make something different without preparing a complicated pasta sauce, try this Japanese Napolitan spaghetti recipe with ketchup and sausage you may already have at home. The most important step is cooking the sauce long enough to evaporate excess moisture, which helps create the rich, mellow flavor Napolitan is known for.
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※ This recipe was prepared and written after referring to a recipe introduced on the YouTube channel ‘일식예보’, then cooking it and documenting the process and results.