Chop the small white onion.
Open the can of tomato sauce. Open, drain and rinse the cans of red kidney beans and black beans.
In a large skillet, brown the ground beef with the chopped onion and minced garlic. Drain, if needed.
To the slow cooker, add the browned ground beef with the red kidney beans, black beans, tomato sauce, salsa, beef broth, chili powder, and cumin. Stir it well and then set on low for 8 hours. Once cooked, season with salt and pepper to taste.
Warm the dinner rolls.
Serve Slow Cooker Cowboy Chili with shredded cheese garnish, and side of veggies and dinner rolls.