In a bowl, gently combine ground beef, seasoned salt, dried oregano, black pepper, garlic, onion powder, egg, breadcrumbs, and Worcestershire sauce. Form the mixture into 4 equal patties.

Heat olive oil in a large skillet over medium heat. Cook the patties for about 4-5 minutes per side until browned. Remove patties and set aside. In the same skillet, add the sliced onion and cook until soft, about 4 minutes.

Sprinkle with flour and stir well. Gradually pour in beef broth while stirring to form a smooth gravy. Let the mixture simmer for about 5 minutes until thickened. If it becomes too thick, add a splash more of broth to thin it.

Return the patties to the skillet, spoon the gravy over them, and cook for an additional 5-10 minutes until the patties are cooked through. Garnish with fresh parsley.