1 large onion, sliced
2 to 3 lb. boneless chicken breast
2 tsp. salt
1/4 tsp. pepper
2 tbsp. mustard
1/4 c. vinegar
1/2 c. maple syrup
1/2 c. chili sauce

Put onion slices in pan. Place chicken on top of onion. Sprinkle with salt and pepper. Combine remaining ingredients and pour over chicken. Simmer, covered, basting with the sauce. Add water if it becomes too thick. Cook 45 minutes to 1 hour at 350°F.