peeled, seeded and chopped PLACE THE BEANS in a pot and fill it with water 10 cm above the beans. Add the ham hock, cover and place over high heat. Bring to a boil, reduce heat to low and simmer for 3 hours. Add water as necessary during the cooking so that the beans are always barely covered. Remove cover during the last hour and let the liquid thicken a bit. Add salt and pepper at the end. Meanwhile, heat the oil in a skillet, add the onion and peppers and cook until soft, about 7 minutes. Add the tomatoes and cook another minute. When it's time to serve the beans, mix the onion, pepper and tomatoes to the beans.