Black Bean Soup

Slice and reserve the bacon rind. Cut the bacon into quarter-inch cubes. Put the bacon and rind into a heavy kettle or casserole and cook, stirring often, until the fat is rendered. The bacon should be well-browned and crisp. Add onions, celery, carrots, bay leaf, garlic, 3 T of the cumin, thyme, black pepper, and oregano. Stir to blend and cover. Cook approximately 5 minutes over moderately low heat. Do not allow the mixture to burn. Add the dry beans (cleaned of rocks etc) and mix together. Cover and let stand 30 minutes, then add the tomato paste and stir briefly. Add the chicken stock and bring to a boil. Cook, covered over moderate approximately 2.5 hours, skimming the surface to remove foam occasionally. The soup is ready when the beans are soft and some of them have disintegrated. Stir in the lime juice, cayenne pepper, salt, coriander, and remaining cumin. Remove and discard the bacon rind and Bay leaf. Ladle the soup into individual bowls. Garnish with sour cream and salsa on top.