Brown the ground beef with the chopped onion in a medium skillet over medium-high heat. Drain grease from meat if necessary.
Pour ground beef mixture into the slow cooker. Add the tomato sauce, diced tomatoes, beans, and seasonings to the crockpot. Stir. Cook on low for 6-8 hours or high for 4-5 hours.
Right before serving, stir one cup of the cheese into the chili. Top with remaining cheese and Fritos.
Serve with more chips, sour cream, letttuce, tomato as desired.
