cook bean according to package directions. preheat oven to 350 degrees. coat a 13x9 inch baking dish with non stick spray. Saute onion and garlic for 3 minutes. add chili powder and cumin saute for 1 minute. add half the tomatoes, corn, chiles, salt and pepper, simmer for 1 minute. wrap the tortillas in aluminium foil and warm them for 5 minutes. In a food processor with the metal blade, process beans and sour cream until smooth. add to skillet and cook until bean are warm about 3 minutes. divide the bean mixture among the tortillas. roll and place seam side down in the prepared baking pan. top with remaining tomatoes and cheese. Cover with foil, bake until the cheese melts about 20 minutes