To start, slice up the onion. In a small bowl, combine the onion soup mix, gravy mix, cornstarch, cream of mushroom then slowly whisk in the beef broth. Once combined pour into the crockpot.
Lay the cube steaks in the crockpot on top of the gravy then place the sliced onions directly on top of the steaks.
Cook on high for 3-4 hours or low for 5-6 hours. The time will vary on how thick the steaks are and how many you're trying to cook.
Once finished, serve with rice or over mashed potatoes.