1. For sauce, in a 1-1/2-quart saucepan cook onion and garlic in hot oil until tender. Stir in tomato sauce, brown sugar, vinegar, Dijon-style mustard, thyme, and pepper. Bring to boiling; reduce heat. Simmer, uncovered, for 15 minutes, stirring occasionally.
2. Skin chicken, if desired. Arrange chicken in a 15x10x1-inch baking pan. Pour half of the sauce over chicken.
3. Bake, uncovered, in a 375 degree F oven for 50 to 60 minutes or until chicken is tender and cooked through, basting occasionally with additional sauce. Serve chicken with any remaining sauce. Makes 6 servings.