Brown beef in a 5 to 6 quart deep pot over medium-high heat, about 5 minutes, breaking up meat with wooden spoon but leaving some large pieces. Add frozen chopped peppers, beans, corn, chiles, soup mix, 2 cups water, cumin, salt, oregano and cayenne. Simmer, covered, 10 minutes. Stir 1/4 cup water into flour in small cup until smooth. Stir into stew; cook until thickened, about 1 minute.