Step 1: In a large bowl, whisk together the egg, milk, breadcrumbs, 1 tsp Worcestershire sauce, onion powder, and garlic powder to form a paste.
Step 2: Add the ground beef to the bowl and gently mix with your hands until just combined; do not overwork the meat.
Step 3: Divide the mixture into 4 equal portions and shape them into oval-shaped patties about 3/4-inch thick.
Step 4: Heat olive oil in a large skillet over medium-high heat. Sear the patties for 3-4 minutes per side until a deep brown crust forms. Remove patties and set aside.
Step 5: In the same skillet, add the butter and mushrooms. Sauté for 5-7 minutes until the mushrooms are browned and tender. Add the minced garlic and cook for 1 minute.
Step 6: Sprinkle the flour over the mushrooms and whisk for 1-2 minutes to cook the flour. Slowly pour in the beef broth and the remaining Worcestershire sauce, whisking constantly.
Step 7: Bring the gravy to a simmer. Once it begins to thicken, return the patties to the pan. Cover and simmer on low for 10-15 minutes until the beef is cooked through.
Step 8: Garnish with fresh parsley and serve immediately over mashed potatoes or noodles.