Pre-cook the sausages:
Fry the sausages in a pan with a little oil until golden brown.
Then cut them into pieces and set aside.
Prepare the sauce:
In the same pan, add a little oil if necessary.
Fry the onion until translucent.
Add the garlic, bell pepper (if using), paprika, pepper, chili pepper, and tomato paste.
Cook for 2-3 minutes, stirring.
Add the tomatoes:
Pour in the chopped tomatoes, add the bay leaf, and a little water if necessary to loosen the sauce.
Add salt to taste.
Simmer with the sausages:
Add the sausage pieces to the sauce.
Cover and simmer over low heat for 20-30 minutes, until the sauce is well reduced.