Soak the beans in water for 10 to 12 hours.
First, peel and wash the vegetables: tomato, onion, bell pepper, and garlic.
Prick the butifarra sausage so it releases its juices and cooks evenly.
Place the beans, whole vegetables, and butifarra sausage in a pot.
Add the sweet paprika, food coloring, and salt.
Pour in enough water to almost cover the ingredients, but not completely, so the dish doesn't turn out too watery.

Close the lid and cook on high heat for 7 hours.
In a skillet, heat a generous amount of olive oil, cook the mushrooms, and set aside.
One hour before the end of cooking, remove the tomato, bell pepper, onion, and garlic from the pot and blend them.
Remove the butifarra sausage and cut it into pieces.
Add everything back to the pot, stir, check the salt, and let it finish cooking for the last hour.