Spray non stick spray into slow cooker. On the stovetop brown ground beef with onions until meat is no longer pink, drain grease and put into Crockpot.
Add all other ingredients EXCEPT cheese. Stir together, close lid and cook 3 hours on high or 6 hours on low heat.
Stir in 1 cup of your cheese, it will melt quickly. Serve in bowls with remaining cheese sprinkled on the top of each bowl.
Garnish with slices of avocado, sour cream, fresh diced tomatoes, chopped cilantro, etc.