Roast Leg of Lamb with Flageolet beans

This classic of French bourgeois cooking might make up a solid Sunday lunch or a serious meal in a good bistro. Flageolet beans, even when dried, are pale green and smooth. (If they’re wrinkled, they’re old.) They can be soaked and then simmered in water for about 15 hours or cooked for 20 minutes in a pressure cooker. Classic recipes call for tossing the cooked beans with a sauce bretonne, a simple garlic and tomato sauce, but I prefer stirring the cooked beans around in the roasting pan,