My Version of Taco Soup

1 lb ground beef
1 medium onion, chopped
1 (16oz) bottle taco sauce
1 (15oz ) can black beans, drained & rinsed
1 (15oz) can dark kidney beans, drained & rinsed
1 (15oz) can whole kernel corn, drained
1 can mild rotel tomatoes and green chilies
1 (8oz) can tomato sauce + 1 can water
2 tsp chili powder
1 tsp cumin

Brown ground beef and onion together; drain.  Return meat to pot and stir in all other ingredients.  Bring to a boil, stirring occasionally.  Reduce heat and simmer for at least 5 to 7 minutes [allowing it to simmer longer will just allow the ingredients to mix together more].