4 skinless, boneless chicken breast halves

2 tablespoons butter or margarine

2 cups sliced fresh mushrooms

1 (12-ounce) jar Heinz Fat Free Classic Chicken Gravy®

½ cup milk

2 tablespoons Dijon-style mustard

In large skillet, cook chicken in melted butter until browned on both sides. Remove chicken from skillet. Cook mushrooms in skillet until tender. Stir in remaining ingredients; return chicken to skillet. Cover and simmer 20 minutes or until chicken is done.