Collect all the ingredients.
Combine the ground beef, bread crumbs, egg, Worcestershire sauce, salt, onion powder, garlic powder, and pepper in a large bowl. Mix until fully combined, then shape the mixture into 8 balls and flatten them into patties. This step ensures the flavors are evenly distributed throughout the beef, and forming the patties allows for even cooking while maintaining a juicy texture.
Heat oil in a large skillet over medium heat. Add the patties and onions, frying until the patties are golden brown and cooked through, about 4 minutes per side. Transfer the patties to a plate and keep them warm. This step ensures the patties develop a crispy, browned exterior while the onions caramelize, adding depth of flavor to the dish.
Sprinkle the flour over the onions and drippings in the skillet. Use a fork to stir the flour, scraping up the browned bits of beef from the bottom of the skillet. Gradually add the beef broth and sherry, then season with seasoned salt. Simmer over medium-low heat, stirring occasionally, until the gravy thickens, about 5 minutes. This step allows the flour to create a rich, smooth gravy, incorporating the beef's flavor from the skillet drippings, while the broth and sherry add depth and complexity to the sauce.
Reduce the heat to low, return the patties to the gravy, cover, and simmer for about 15 minutes, or until the patties are fully cooked through. This step allows the patties to absorb the rich flavors of the gravy, ensuring they stay moist and flavorful while finishing cooking.
Plate the dish and enjoy!