Savory Salisbury Steak
- Whisk milk and potato flakes in a large bowl. Add beef, salt and pepper to taste, minced onion, parsley, egg, beefy-onion soup mix and Worcestershire sauce and mix until combined. Shape into four 1/2-inch oval patties and transfer to plate. Refrigerate for at least 30 minutes or up to 4 hours.
- Melt 1 Tbsp. butter in a 12-inch non-stick skillet over medium-high heat. Cook patties until well browned on each side, about 10 minutes. Transfer to plate.
- Add onion and remaining 3 Tbsp. butter to now-empty skillet and cook until onion is softened, about 5 minutes. Add mushrooms and 1/2 tsp. salt and cook until liquid has evaporated, about 7 minutes. Stir in tomato paste and flour and cook until browned, about 2 minutes. Slowly stir in broth and wine and bring to a simmer. Return patties to skillet, cover, and simmer over medium low heat until cooked through, 15-20 minutes. Season sauce with salt and pepper to taste.
- Serve with mashed potatoes, buttered egg noodles or rice.