This is an oven method that is very popular in Italy, particularly in Tuscany. The beans are soaked overnight and then rinsed and placed in a pot or casserole for an easy and delicious dish.
Preheat the oven to 275 degrees.
Add the onions and beans to a large pot or casserole dish and cover with water by ½ an inch.
Cover and bring the water to a near boil over low heat.
Place the pot in the oven and bake until beans are tender (45 minutes to 1 hour). Make sure the water does not evaporate during cooking to below the level of the beans. Remove from oven and season with salt and pepper, to taste. Let stand for about 10 minutes.
Drizzle a tablespoon or two of olive oil over beans and serve.