Crockpot mystery roast beef has a secret ingredient inside. You'll never guess what it is, but the chunks of beef roast and savory gravy are perfect served over mashed potatoes, rice, or egg noodles.
Put the meat into your crockpot and add the 10.5 ounces cream of mushroom soup, 6.5 ounces canned mushrooms, 1 ounce package dry onion soup mix, and 1½ cups ginger ale. Cook on low for 6-8 hours.
Stir and serve over mashed potatoes, rice, or egg noodles.