TO MAKE THE BUTTER BEANS
Soak the beans overnight in water. The next day, simmer them in 10 cups water with the bouquet garni, onion, and olive oil until the beans are soft, about 1 to 2 hours. Season with salt to taste. The beans can be cooked up to two days in advance and stored in their cooking liquid.
TO MAKE THE LAMB
Season the lamb generously with salt and black pepper. Use a peeler to remove the peel of one lemon and lay the peel on the lamb along with the pounded garlic and chopped rosemary. Drizzle the lamb with olive oil and massage the lamb with your hands to distribute the seasoning and lemon oil. Let the meat marinate in the refrigerator for 2 hours, or better yet overnight.
Grill the lamb ribs over medium heat for about 30 minutes, flipping them over halfway through cooking. Alternatively, roast them in a 375-degree oven for 45 minutes. Turn on the broiler for the last few minutes if they need more color.
To plate, heat the beans in a wood oven, on a grill, or on your stove top in a cast-iron pan. Cut the grilled ribs and serve atop the beans. Finish with a fresh squeeze of lemon juice and flaky salt.