Black Bean Soup with Coriander and Red Onion

1 pound black beans, soaked overnight in water to cover by 1 inch
2 tablespoons annatto oil (1/2 cup olive oil, 2 tablespoons annatto seeds (Heat olive oil in a saucepan over low heat. Add annatto seeds and cook for 5 minutes or until oil is a rich orange color. Remove from heat; cool and strain. Discard seeds).
8 ounces ham steak, finely chopped
1 1/2 cups chopped red onion
4 garlic cloves, minced
2 bay leaves
1 tablespoon ground cumin
1 tablespoon minced fresh oregano
2 tablespoons tomato paste
4 cups chicken stock
1/4 cup chopped coriander (cilantro)
2 tablespoons distilled white vinegar
salt and pepper to taste
cooked white rice and coriander leaves for garnish

Drain beans, reserving liquid.

In a heavy-bottomed 3 to 4 quart saucepan, heat oil over moderate heat until hot. Add ham and sauce until lightly golden.

Add 1 cup of onion and the garlic; cook about 10 minutes until softened.

Add the next 4 ingredients and cook for 5 minutes.

Deglaze pan with the chicken stock, scraping up the brown bits from the bottom with a wooden spoon.

Add beans and 6 cups of the bean soaking liquid (adding water if necessary to make 6 cups). Bring mixture to a boil; lower to a simmer and cook, skimming any froth that rises to the surface, for at least 2 hours or until the beans are very soft.

Remove pan from the heat and discard bay leaves. Puree soup in a blender in batches, adding additional water to achieve desired texture. Return to the pan and heat over low heat for 15 minutes or until soup is heated through.

Just before serving, stir in coriander, vinegar and salt and pepper to taste. Serve with remaining chopped red onion, coriander leaves and rice to garnish.