Turkey Chili

1 yellow onion
1 red bell pepper
1 pound extra lean ground turkey
1 (28-ounce) can diced or crushed tomatoes
1 1/4 cups chicken broth
2 (15 oz) cans dark red kidney beans
1 (15 oz) can sweet corn
garlic, chili powder, cumin, oregano, cayenne pepper, toppings