La Gran Cocina Black Bean Soup

I love this new cookbook, which is an encyclopedia of Latin American cooking.  You can only eat it during Passover if you are following the Torah's rules and not going by any Ashkenazi traditions--when i was in Poland before Passover last year I realized that the things that Polish Jews avoided during Passover were largely not an issue because they avoid them much of the rest of the year.  I eat like a Mediterranean all the other weeks of the year, so those are the rules I follow during Passover.

Beans
450 g (1 lb/2 cups) dried black beans
2 L (8 cups) water
1 small yellow onion, peeled
1 small green pepper, cored and seeded
1 bay leaf
Sofrito
60 ml (1/4 cup) extra-virgin olive oil
4 large garlic cloves, minced
1 small yellow onion, minced
1 medium green bell pepper, cored, seeded and minced
1 cubanelle pepper, seeded and finely chopped (or 10 Aji dulces)
1 bay leaf
10 ml (2 tsp) ground cumin
10 ml (2 tsp) dried oregano
Soup
15 ml (1 tbsp) red wine vinegar
10 ml (2 tsp) salt (or to taste)
2 ml (1/2 tsp) ground black pepper
1 large red bell pepper (optional)
10 ml (2 tsp) sugar

1. For beans, in a heavy pot, combine beans, water, onion, green pepper and bay leaf, then bring to boil over high heat. Lower to medium and simmer 1 1/2 hour or until beans are tender.
2. If using red bell pepper (I recommend!), preheat oven to 400°F. Place red pepper (why not make some more while you’re at it) on a cookie sheet and roast until black, around 45 minutes or so. Remove, transfer to a bowl, seal with plastic wrap and let cool. When cold, peel off skin, seed and chop. Make sure to keep the liquid at the bottom of the bowl.
3. When beans are soft, discard onion, pepper and bay leaf. Remove a good 1/2 cup of beans and mash into a purée. Reserve. Keep beans on low while you make the sofrito.
4. For sofrito, heat oil in a heavy skillet over medium-high heat. Add garlic and sauté 20 sec. Add onion, peppers and bay leaf, then sauté 5 minutes or until soft. Add cumin and oregano, then stir-cook 1 minute. Incorporate mashed beans and cook 1 minute.
5. For soup, add sofrito to pot along with vinegar, salt, pepper, sugar and reserved red pepper with their liquid (my addition BTW). Simmer over low heat 30-45 minuts or until creamy. Remove bay leaf.