Tender and juicy CrockPot steak made with mushrooms and onions and a flavorful A-1 sauce gravy. Perfect slow cooker meal for the whole family. Easy weeknight meal.
Combine steaks and ½ cup steak sauce in a large zippered plastic bag. Massage contents to coat evenly. Refrigerate at least 1 hour, up to overnight.
Remove steaks from marinade. Heat oil over medium-high heat in a large skillet. Add steaks and brown, turning once, about 2 minutes per side. Remove skillet from heat.
Layer mushrooms, onions, and browned steaks in a 6-quart CrockPot. Deglaze skillet with a small amount of water and add pan juices to the slow cooker. Sprinkle in salt and pepper and pour in the remaining ½ cup A1 sauce.
Cover. Cook on low for 6 hours or on high for 3 hours, until meat is cooked through and tender.