Salisbury Steak with Mashed Potatoes

For the Salisbury Steak:
Prepare the Patties: In a bowl, combine ground beef, bread crumbs, finely chopped onion, egg, ketchup, Worcestershire sauce, garlic powder, salt, and pepper. Mix well until all ingredients are incorporated.
Shape Patties: Form the mixture into 4 oval patties.
Cook Patties: Heat olive oil in a skillet over medium heat. Add the patties and cook until browned on both sides. Remove and set aside.
Make the Gravy: In the same skillet, add beef broth and bring to a simmer. If using, add sliced mushrooms.
Simmer Patties: Return the patties to the skillet. Cover and simmer for 10-15 minutes. ⏱️
Thicken the Gravy: Remove the patties. Stir the cornstarch mixture into the skillet to thicken the gravy. Return the patties to the skillet and coat with the gravy.