Taco Soup

1 onion, chopped (or 1/4 cup dried onions)
1 (16 ounce) can red chili beans, drained
1 (15 ounce) can black beans, drained
1 (15 ounce) can refried beans
1 (15 ounce) can whole kernel corn, drained
1 (8 ounce) can tomato sauce
1 (12 fluid ounce) can of chicken stock
2 (10 ounce) cans diced tomatoes, undrained
1 can chopped green chilies, drained
1 (1.25 ounce) package taco seasoning
1 (12.5 ounce) can chicken, undrained
sliced olives (optional)
shredded Cheddar cheese (optional)
sour cream (optional)
crushed tortilla chips (optional)

Place the onion, chili beans, black beans, corn, tomato sauce, chicken stock, diced tomatoes, green chilies, canned chicken, and olives in a slow cooker. Add taco seasoning, and stir to blend. Set slow cooker to low heat, cover, and cook for 5 hours.

Serve topped with shredded Cheddar cheese, a dollop of sour cream, and crushed tortilla chips, if desired.