Trim, peel, and thinly slice <quantity>1</quantity> medium onion

Trim, deseed, and thinly slice <quantity>1</quantity> small red bell pepper

Thinly slice <quantity>6</quantity> white button mushrooms

Peel and mince <quantity>2</quantity> garlic cloves

Cut <quantity>3<unit>slices</unit></quantity> of bacon into <quantity>1<unit>in</unit></quantity> pieces

Thinly slice <quantity>6</quantity> smoked Japanese sausages

Add the bacon to a skillet over medium-high heat. Fry until crispy and transfer to a plate lined with paper towels

Add the sliced onion and <quantity>1<unit>tsp</unit></quantity> of vegetable oil to the skillet. Stir and cook until the onion softens

Add the minced garlic and the Japanese sausages. Stir and cook for 4m until lightly browned

Add the mushrooms and red bell pepper. Stir and cook for 4m until the vegetables soften

Add <quantity>¾<unit>cup</unit></quantity> of ketchup and stir to combine. Cook for 3m until it starts to boil

Add <quantity>8<unit>oz</unit></quantity> of cooked spaghetti and <quantity>1<unit>tbsp</unit></quantity> of unsalted butter. Stir until everything is well combined

Add <quantity>2<unit>tbsp</unit></quantity> of the pasta’s cooking water. Add the fried bacon and stir to combine. The ketchup and sausage spaghetti is ready

Pair it with some hot sauce or grated parmesan cheese and enjoy!