Combine the chicken breast, onion, and garlic in the bottom on the slow cooker. Sprinkle a little salt and pepper over the top of the mixture.
Add diced tomatoes, water, black beans, kidney beans, corn, and avocado to the slow cooker. Stir gently and add salt, pepper, and cumin.
Mix well and cover, set your slow cooker for 3 hours on high heat.
When it’s finished cooking, give the soup a stir and ladle into soup bowls. Garnish with your favorite toppings - we love cheese, cilantro, and sour cream