Dr. Punam Hills shares a favorite recipe of hers. Yields: 8 servings Ingredients 6 8-inch fat-free flour tortillas 1 Tbs. olive oil 1 small onion, chopped (1 cup) 2 Tbs. chili powder 2 tsp. ancho chile powder 2 cloves garlic, minced (2 tsp.) 2 cups strained tomatoes,...