Japanese ketchup spaghetti or Napolitan is almost like Pinoy spaghetti. It uses ketchup as a major component for the sauce. While spaghetti Napolitan traditionally uses tomato ketchup (supposedly since tomato sauce was a rare ingredient in Japan in the 1950s), for this recipe, we give it a Pinoy spaghetti twist. Instead of tomato ketchup, we’re using banana ketchup.
Fermented banana ketchup
A popular Philippine condiment, banana ketchup first appeared in Filipino households during the second World War because there was a shortage of tomatoes. We made our own banana ketchup using fermented bananas, along with the starter liquid of fermented garlic, water and salt. Ketchup, like soy sauce and vinegar, was traditionally made through fermentation. It was originally fermented fish sauce that sailors brought with them and found its way to different ports and adapted with local ingredients.
What we love about fermented banana ketchup is that it has none of the refined sugars and corn syrup found in popular banana ketchup brands. What it has, is plenty of live microorganisms good for your gut. Use it as you would store-bought ketchup, as a dip, marinade, and yes, pasta sauce.

Quick weeknight meal
We tried the banana ketchup on spaghetti Napolitan, because it cooks faster than Pinoy spaghetti. Our sweet homegrown pasta dish needs ground beef or pork, which typically requires an hour to cook. The usual Napolitan just uses Japanese sausage or ham and mushrooms, so you can have it ready in 15 minutes. When I don’t want to spend too much time in the kitchen (especially at weeknights), I’m always looking for dishes that cook quickly.
This version has no meat, but we used Worcestershire sauce. For the vegan version, you can substitute it with soy sauce. We also didn’t have to add sugar as banana ketchup is already quite sweet.
Ingredients
- 7 oz spaghetti noodles (good for 2 servings)
- ¼ cup reserved pasta water
- 1/3 cup banana ketchup
- 2 tsp Worcestershire sauce (or soy sauce)
- ½ Tbsp plant-based milk
- 1 Tbsp oil
- 2 cloves garlic, minced
- ½ onion, sliced
- 1 green or red bell pepper, sliced
- ½ cup mushrooms, sliced thinly
- Salt and pepper
- 1 Tbsp unsalted butter (optional)
Directions
1. Cook the pasta according to package directions. Once cooked, set aside ¼ cup pasta water.
2. While noodles are cooking, make the Napolitana sauce: mix the ketchup, Worcestershire sauce, and milk. Set aside.
3. In a pan, saute garlic in oil over medium heat for at least a minute. Add the onions and cook until wilted.
4. Toss in the bell peppers and mushrooms. Season with salt and pepper.
5. Once everything is cooked, pour the Napolitana sauce. After it starts to bubble, make sure to mix it with the vegetables.
6. Add some of the reserved pasta water to the mix. You don’t have to completely use all of the ¼ cup of pasta water, it will depend on the consistency of the sauce you want. Let it simmer.
7. Add the drained spaghetti noodles into the pan. You can toss in butter and make sure all noodles are coated with the sauce. Enjoy!
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