Prep your ingredients: chop one medium onion finely and rinse and drain two cans of kidney beans.

If desired, brown one pound of ground beef in a skillet until fully cooked, adding onions in the last few minutes.

Combine the cooked beef and onions in the crockpot, or add raw ground beef if skipping browning.

Add kidney beans, diced tomatoes, and chili seasoning to the crockpot; stir to combine.

Cover and cook on low for 6-8 hours or high for 3-4 hours.

Check beef is fully cooked before serving; serve hot with crusty bread or rice.