Start the preparation the day before. Ask the butcher to trim the saddle and cut out 6 medallions. Ask him to give you the bones. Put the medallions in a bowl. Place the vegetables on top, add thyme, bay leaf, salt, pepper and the bones. Bring the red wine to a boil and pour over. Add 1/2 cup oil and refrigerate overnight. The next day take out the meat and the bones. Dry them. Brown the bones in butter. Sprinkle with flour and stir. Add the marinade strained from the vegetables. Add the stock cube and 1 1/2 cups water. Simmer for 1 1/2 hours to 2 hours, until the liquid reduces by half. Strain the sauce into a small saucepan. Cook the lamb medallions in 4 tablespoons butter and 2 tablespoons oil over brisk heat until they are brown on both sides and pink in the center. Remove them to a warm place. Whisk 4 tablespoons butter by the cube into the sauce, pulling the pan off and on the heat, and continuously whisking. Taste for seasoning and adjust if needed. Place the medaillions on a platter and coat with sauce. Serve with fresh buttered pasta.
