Southwestern Bean Soup

This is one of those recipes, like taco soup, that hardly bears writing down.  It's basically taco soup with beans instead of meat.

Southwestern Bean Soup
1 small onion chopped
1 t. garlic
1/2 t. vegetable oil
1 can black beans
1 can diced tomatoes
1 can chicken broth
1 can cannelloni or white kidney beans
1 can corn
3/4 t. cumin
3/4 t. chili powder

Saute onion and garlic.  Stir in remaining ingredients and bring to a boil.  Simmer for 5 minutes.  Serve with tortilla chips, shredded cheese, and sour cream.