Gather all required ingredients to ensure a smooth cooking process.
In a slow cooker, combine the diced tomatoes with green chiles, chili beans, black beans, corn, beer, tomato sauce, and chopped onion. Sprinkle in the taco seasoning, stirring thoroughly to blend all components.
Place the chicken breasts on top of the mixture, pressing them down gently until they are partially submerged in the liquid.
Cover the slow cooker and cook on a low setting for approximately 5 hours.
Once the chicken is fully cooked, transfer it to a cutting board and allow it to cool until it can be easily handled. Shred the chicken using two forks, then return the shredded pieces to the slow cooker.
Continue to cook the soup on low for an additional 2 hours, allowing the flavors to meld together.
Serve the soup hot, garnished with shredded Cheddar cheese, a spoonful of sour cream, and a sprinkle of crushed tortilla chips for added texture and flavor.