Cut the sausages into bite-sized pieces.

Slice the onion thinly and cut the green pepper into thin strips.

Boil water in a pot, add salt (not listed in ingredients), and cook spaghetti 1 minute less than the package instructions. Reserve 2 tbsp of the cooking water and drain the rest.

Heat half the butter in a frying pan over medium heat. Add the sausages and onion, and cook until lightly browned.

Add the seasonings (ketchup, consomme, salt, and pepper) and cook until the liquid evaporates.

Add the spaghetti, reserved pasta water, green pepper, and the remaining butter. Stir-fry until everything is well combined.