Leaf lettuce In skillet, saute chicken, onion and green pepper in oil until vegetables are tender-crisp and chicken is tender. Stir in beans, horseradish sauce, salt and pepper. Simmer 5 minutes to blend flavors. Cut pitas in half and tuck 1 tomato slice and lettuce into each half. Fill each with about 1/3 cup bean mixture. Makes 4 servings (about 3 cups mixture)