Add the remaining 1 tablespoon of oil to the casserole and add the bacon. Cook over moderate heat, stirring a few times, until the bacon is lightly browned, about 3 minutes. Add the onions and cook, stirring a few times, until softened. Add the wine and boil over high heat until slightly reduced, about 2 minutes. Add the stock, thyme, garlic and bay leaf. Return the lamb to the casserole along with any accumulated juices. Cover with a sheet of parchment paper and the lid. Braise in the oven for 1 hour.