The night before, put the beans, water, bay leaves, salt and green pepper in a soup pot to soak overnight.
Next morning, turn on the heat to low-medium and let it cook for about 1-1/2 hours. (Keep an eye on the water, and as it reduces, add water to maintain about the same level.)
After the 1-1/2 hours of cooking (beans should be quite soft by then), in a skillet, heat the olive oil, chopped onion and garlic. When it starts to smell “heavenly,” add the cooked green pepper, and 3 or 4 ladles of the cooked beans (without the water) to the skillet. Take a potato masher and mash the beans with the pepper and onion mixture. Once the texture is kind of pasty, mix in the oregano and cumin, then add it back to the beans and water with 1 tsp. of vinegar. (The beans water should be black by now.) Cover the pot and let it cook for about 1/4-hour on medium-high, then lower the temperature to simmer for about 1 hour more. (Keep checking the water so it doesn’t evaporate too much, but remember that the beans are at their best when they are kind of thick, not watery.)
Before you serve, squirt in about 1/4-cup of extra virgin olive oil.
Serve with arroz blanco (white rice) and pan (bread).
Note: Cumin, oregano and frijoles can be bought in any supermarket. The beans are on the Spanish food side, and the cumin (comino en polvo) and oregano (oregano en polvo) can be found in the spices section.