Gratin of Flageolet Beans and Sausage

FOR THE BEANS: Pick over the beans. Soak if desired and drain. In a large, heavy-based pot, cover the beans with 8 cups cold water. Add the onion, garlic, bay leaf, sage, and thyme; bring to a boil over high heat. Reduce the heat to a bare simmer, skimming any foam that rises to the surface. Simmer gently until the beans have softened, about 1 and 1/2 hours. Add the salt and continue cooking until the beans are quite tender, 20 to 30 minutes longer. Allow the beans to cool in the broth. Refrigerate overnight to let the flavors meld.

FOR THE GRATIN: Heat the oven to 450 degrees. Drain the beans, reserving the cooking liquid. Discard the garlic and any stems from the herbs. In a frying pan, heat 4 Tbs. of the olive oil over medium heat. Add the onions, 1/4 tsp. salt, and 1/4 tsp. pepper; cook until the onions are soft and lightly browned, about 10 minutes. Add the thyme, sage, and garlic; cook 1 minute longer.

In a large mixing bowl, combine the beans with the onion mixture. Taste for seasoning and add more salt and pepper if needed. The mixture should be highly seasoned. Transfer the beans to a shallow 2 1/2 qt. casserole.

In a hot frying pan, brown the sausages well on all sides. Let the sausages cool before cutting them into 1 1/2 -inch thick slices. Arrange the sliced sausages over the beans, then push them down beneath the surface of the beans with a wooden spoon.

Bring the reserved cooking liquid to a boil and pour enough of it into the casserole to barely cover the beans (add chicken stock if there isn’t enough). Sprinkle the bread crumbs over the top and, with a wooden spoon, push them down a bit to absorb some of the liquid. Drizzle the remaining 2 Tbs. olive oil over the top. Cover with aluminum foil, set the pan on a baking sheet to catch any drips, and bake for 30 min. Reduce the heat to 325 degrees and continue cooking for 45 minutes. Remove the foil and cook until the surface is golden brown and the juices are bubbling, about 15 minutes longer.