** See recipes for Bordelaise Sauce, and Veal Stock. For Sauce: ========== Place the reserved sweetbreads in a small saucepan; add enough cold water to cover. Add the onion, 2 tablespoons shallot, 1/4 teaspoon thyme, 2 bay leaves and salt and pepper. Bring to a boil, reduce heat and simmer for 8 minutes. Remove the pan from heat and let it cool. Drain the sweetbreads and remove all remaining connective tissue; separate into bite-sized pieces. Go on to the next recipe to learn how to put together and cook the pasta, sauce and filling.