Southwest Chicken Corn Chowder

Name: Southwest Chicken Corn Chowder
Ingredients: * 3 tablespoon butter; * 3 tablespoon flour; * 1/2 an onion chopped; * 1/2 red and 1/2 green bell pepper chopped; * 1/4 tsp cumin; * 1/2 tsp chili powder; * 1/4 tsp pepper; * a dash of cayenne pepper for spice (optional); * 2 1/2 cup low sodium chicken broth; * 1 can white or great northern bean drained; * 1 can chili bean drained; * 1 1/2 cup shredded cooked chicken; * 3/4 cup frozen whole corn kernel; * 1 cup sour cream; * 1 1/2 cup cheese (cheddar, monterey jack, or mexican blend); * corn chip and chopped roma tomato for serving