Crock Pot Salisbury Steak

Instructions

1. Place the sliced 6 ounce mushrooms & ½ large onion, sliced in the bottom of the crock pot.
2. In a medium-sized mixing bowl, add 1 pound ground beef, 1/2 cup bread crumbs, 2 tablespoons ketchup, 1 tablespoon Worcestershire sauce, 1 teaspoon mustard powder, 1 egg, salt and pepper,. Mix with your hands until combined, then shape into 4 oval patties.
3. Heat 2 tablespoons butter in a medium-sized skillet over medium-high heat. Add the patties and cook for 3 minutes on each side. They don't need to be cooked all the way through, just browned.
4. Layer the patties over the mushrooms and onions.
5. In a medium bowl, add 2½ cups beef broth, 2 tablespoons ketchup, and 2 tablespoons Worcestershire sauce and whisk to combine. Pour over the beef patties.
6. Cook on high for 3 hours or low for 5 hours.
7. Remove the patties from the crockpot and set aside. In a small bowl, add 2 tablespoons cornstarch and 1 tablespoon water, creating a slurry. Stir into the broth and let cook a few minutes until thickened. Add the beef patties back to the crock pot and gently toss to coat the patties in the sauce.
8. Garnish with fresh chopped parsley and serve over mashed potatoes.