Combine the ground chuck, salt, ground black pepper, onion salt, and garlic powder in a medium-sized bowl. Mix to combine well.
Form the meat mixture into 4 equally sized round, flat patties.
Heat a cast-iron skillet to medium-high heat.
Place the hamburger steaks in the hot skillet, being careful not to crowd the steaks too much. Cook for 3 to 4 minutes.
Flip the steaks over, and cook for 3 to 4 minutes on the other side. The steaks should be seared and browned.
Remove the steaks from the skillet, and set aside.
Onion Gravy
Place the sliced onions in the skillet and cook for 5 to 6 minutes, or until they have softened and begun to brown.
Remove the onions from the skillet.
If there isn’t enough grease in the skillet, add a teaspoon or two of butter. Then add the flour and cook for 1 minute, stirring to make sure the flour cooks evenly.
Add the beef broth to the skillet and stir until the gravy is smooth.
Reduce the heat to low and cook for 2 minutes. You can add the onions to the gravy or keep them separate.
To Serve
Place the hamburger steaks on a plate and top with onions and gravy.