Sopa de Frijoles Negros (Black Bean Soup)

Name: Sopa de Frijoles Negros (Black Bean Soup)
Cuisine: Costa Rica
Ingredients: 1 pound black beans (turtle beans); 1 tablespoon of cooking oil; 1/2 cup of diced onion; 2 cloves of garlic (chopped); 1 chopped green or red bell pepper; 1/2 cup chopped celery; 1/2 cup fresh cilantro (use fresh only!); Salt and pepper to taste