Frijoles negros (black beans in casserole)

For 4 people
200 g of dried black beans
2 white onions
1 green pepper
1 glass of dry white wine
2 cloves of garlic, chopped
white vinegar
salt, pepper
oregano
Laurel
1 teaspoon cumin

Soak black beans overnight.
Wash them well, discard the old ones and cook covered over medium heat with 1 litre of water, half a pepper into strips and onion cut into four.
When they start to become tender uncovered (about 90-120 '), add the spices and wine.
Apart from take a sauce with a little garlic, onions and the rest of the chopped bell pepper: must wither but not Browning.
Together this Fund and two tablespoons of white vinegar, salt and pepper. Cook other 20 '.
Must be a "wet" very often: if it is not dense enough passed a couple of tablespoons of beans and add to sauce.