Prepare the Patties: Shape the ground beef into 4-6 equal-sized patties. Season with salt, pepper, and any other desired spices.
Brown the Patties: Heat a skillet over medium-high heat and add a tablespoon of butter or oil. Brown the hamburger patties on both sides, about 3-4 minutes per side. Remove the patties and set them aside.
Sauté Onions: In the same skillet, sauté the sliced onions until soft and golden, about 5 minutes.
Make the Gravy: To the onions, add the flour and stir until combined. Gradually whisk in the beef broth and Worcestershire sauce. Season with garlic powder, onion powder, salt, and pepper. Let the gravy simmer until it thickens, about 5-7 minutes.
Assemble the Dish: Preheat the oven to 350°F (175°C). In a baking dish, arrange the browned hamburger patties. Pour the gravy mixture over the patties, then cover with foil.
Bake: Place the baking dish in the oven and bake for 30-35 minutes, or until the patties are fully cooked and tender.
Serve: Remove from the oven, discard the foil, and serve with mashed potatoes or your favorite side dishes.