1 pound dried black beans
1 medium onion, finely chopped
1 green bell pepper, finely chopped
3 cloves garlic, minced
1 ham bone or smoked ham hock
1/2 cup olive oil
Salt and freshly-ground black pepper
1/3 cup white or cider vinegar

To garnish:
Sour cream
Chopped raw onion
Chopped red pepper