The original Napolitan had canned tomato puree for its sauce and bacon for the meat. As it evolved over the years and adapted for Japanese home cooking, ketchup and sliced sausages, both cheaper than tomato puree and bacon, became standard ingredients.
As you can imagine, there are so many versions of this simple dish. This recipe was inspired by a tutorial in an episode of Izakaya Bottakuri, a show on Netflix about two sisters who run a diner that they inherited from their parents.

The Naporitan sauce is a mixture of tomato ketchup, Worcestershire sauce, sugar and milk which are stirred together until fully blended.

To cook Naporitan, melt butter in a pan and saute onion, garlic and bell pepper just until starting to soften. Because butter burns fast, remember to set the heat to MEDIUM during this stage.

Add the sliced sausages to the sauteed vegetables and cook, tossing often, until heated through.

Pour in the sauce, stir and allow to boil. Taste and adjust the seasonings, if needed. You might want a different flavor balance and this is the time to customize the taste of the sauce.

Dump in the cooked pasta and toss until every strand of noodle is coated with sauce and the sausages and vegetables are evenly distributed.
Ingredients
- 180 grams spaghetti
- 2 tablespoons butter
- 1 medium yellow onion peeled and thinly sliced
- 2 cloves garlic peeled and chopped
- 1 large bell pepper julienned
- 300 grams sausages (frankfurters were used here) thinly sliced
Sauce
- ½ cup ketchup
- 1 tablespoon Worcestershire sauce
- 1 tablespoon sugar
- 2 tablespoons milk
- ¼ teaspoon pepper
Instructions
- Dump the spaghetti in plenty of boiling water.
- While the pasta cooks, melt the butter in a pan.
- Saute the sliced onion, chopped garlic and julienned bell pepper until a bit softened.
- Add the sliced sausages and cook until heated through.
- Mix together all the ingredients for the sauce and pour into the pan with the sausages.
- Stir and cook until boiling.
- Drain the spaghetti and dump into the sauce. Toss well.
- Serve your Naporitan sprinkled with grated Parmesan.