Add about 1 cup of sliced onions to the slow cooker before adding the steak. Pot roast, pepper steak, French dip—even cabbage rolls. #SlowCooker #Crockpot #SteakDiane … In the same skillet, saute onion for 1 minute. This easy Salisbury steak one of our favorite family meals! Slow Cooker Salisbury Steak. Instead of onion gravy, make the steak and gravy with a packet of mushroom gravy or plain brown gravy. In a skillet, brown steak in oil; transfer to a 5-qt. We serve this on top of garlic mashed potatoes or rice but my all time favorite is serving it over cooked … Pour over the flank steak… Add remaining ingredients; bring to a boil. See all the wonders your slow cooker works with beef. Sauté about 6 to 8 ounces of mushrooms in a small amount of butter or oil until softened. slow cooker. Slow Cooked Steak Diane Casserole - a great make-ahead meal, just thing if you're feeding a crowd! Add them to the sauce mixture. Gradually add water, stirring to loosen browned bits from pan. Beef stew. Cook in the oven, on the hob or in the slow cooker. I love using my slow cooker any time of year!