In a large ovenproof skillet, cook bacon until crisp. Remove, crumble and set aside. Discard all but quarter cup drippings. Trim beef; cut into serving-size pieces. Brown on both sides in drippings. Top meat with mushrooms, tomatoes and onion. Sprinkle with tarragon and bacon. Cover and bake at 160ºC or 1- quarter to 1- 0.75 hours or until meat is tender, basting twice. Remove meat to a serving platter; keep warm. Combine cornstarch and water; add to skillet and bring to a boil. Cook and stir for 2 minutes. Reduce heat; stir in cream. Simmer, uncovered, for 3-4 minutes or until sauce thickens. Serve over meat.