I love not only the flavour, but also the versatility of slow-cooked beans. I make a big batch, because they can be served as is, with a drizzle of fine-quality extra virgin olive oil and some grated Parmigiano-Reggiano on top, or cold as a bean salad. The beans can also be added to soups or pureed and thinned with stock, along with some of the cooking liquid, for a soup. We cook the beans in water, but chicken stock would make the finished dish richer in flavour. Finally, don't salt the beans too early in the cooking, as that would keep them from cooking evenly.
Use an assortment of dried beans that are the same size, since they will all be cooked together.
Spread the beans on a baking sheet and discard any split beans or stones. Place the beans in a strainer and rinse under cold running water; then place in a large container, add tepid water to cover by 3 inches, and leave at room temperature overnight.
The next day, discard any bean skins that have risen to the top of the water. Drain and rinse the beans, and place in a Copper-Core Dutch Oven. Cover the beans with cold water and bring to a boil over medium heat. Drain the beans in a strainer, rinse with cool running water, and then return the beans to the pot. Add the remaining ingredients except the salt; next add enough water to cover the beans by 1 1/2 inches.
Place the pot over medium heat and slowly bring to just under a simmer. The beans should cook very gently-there should be movement to the water but bubbles shouldn't break the surface-so adjust the heat as needed. Cook for about 2 hours, or until the beans are about three-quarters cooked, they will have softened but still have a bit of bite left in them.
Add the salt and cook until the beans are tender, about another 30 to 45 minutes. Pour the beans and their liquid into a container. Once they have cooled, remove and discard the vegetables and bacon; or if you are making soup, reserve some of the vegetables to puree with the beans, if desired. Cover and refrigerate until ready to serve or for up to a week.
To serve as a first course or side dish, reheat the beans with their liquid until hot and season to taste with salt and pepper.
Spoon the beans with a bit of their liquid into serving bowls. Drizzle with olive oil and grate Parmesan cheese over the top.
Garnish with chervil sprigs and roasted tomatoes, if desired. To serve as a soup, reheat the 2 cups beans (and some of the cooked tomatoes, onion, and carrots, if desired) and cooking liquid in a sauce pan. With a slotted spoon, transfer the beans and vegetables, if using, to a blender, reserving the cooking liquid. Combine 1/2 cup of the cooking liquid and the chicken stock in a liquid measuring cup. Puree the beans, adding the stock mixture as necessary until the soup has the consistency that you like. Use the remaining bean liquid if necessary.
Rinse out the sauce pan, return the soup to it, and heat until hot. Season the soup to taste with salt and pepper, then serve in soup bowls with a drizzle of olive oil, a grating of Parmesan cheese and garnish with sprigs of chervil if desired.
To serve as a salad, combine the 2 cups beans and the shallots in a bowl, add the olive oil and red wine vinegar to taste, and stir in the garlic clove. Cover with cling film and refrigerate for at least 1 hour, or up to 1 day. To serve, form a pinwheel of tomato wedges in the center of each serving plate.
Cut the haricots verts in half. Remove and discard the garlic clove. Toss the bean mixture with the haricots verts and stir in the parsley. Spoon the bean salad over the tomato wedges and garnish the plate with cherry tomatoes. Drizzle olive oil over the plate, a sprinkling of fleur de sel and black pepper.
Makes about 7 cups cooked beans, with about 2 cups bean liquid