Place finely grated onion in a mixing bowl; add panko crumbs and stir it all together.
To the mixing bowl add ground beef, minced garlic, egg, ketchup, mustard powder, worcestershire sauce, salt, and pepper; use your hands to mix it all together until well combined.
Shape 4 patties into an oval, to resemble a “steak”, and set aside.
Heat 2 tablespoons olive oil in a large skillet and set it over medium heat.
Add the beef patties to the heated oil and cook for 5 to 6 minutes. Carefully flip them over and continue to cook for 5 to 6 more minutes. Patties are cooked through when the internal temperature registers at 160˚F.
Remove the patties from the skillet and set them aside; keep them covered.
Return skillet to the burner and add 1 tablespoon olive oil. When oil is hot, stir in finely diced onions and cook for 1 minute.
Stir in garlic and then mushrooms; cook for 4 to 5 minutes, or until mushrooms are soft. Add butter and swirl around to melt.
Sprinkle the top with flour and cook for about 30 seconds, stirring constantly.
Pour in the beef broth; mix and stir until everything is combined and there are no lumps from the flour.
Add the beef patties and any juices back to the skillet.
Continue to cook for 5 to 8 more minutes, or until gravy is thickened; stirring occasionally. If gravy starts to thicken too soon, add a bit of water or beef broth to the skillet.
Transfer steaks to a platter.
Taste the gravy for salt and pepper; adjust accordingly.
Forming Patties: To avoid sticky hands, slightly moisten your hands with water when shaping the patties, and don't overmix. Creating an indent in the middle of the patty with your thumb aids in even cooking and keeps them from puffing up in the center.
Seasoning: Adjust the seasonings according to your taste preferences.
Crisp Crust: Ensure both sides of the steaks are well-browned - this enhances their flavor and seals in their juices.
Alternative Poultry Option: Ground turkey or ground chicken can be substituted in this recipe.
Lighter Option: Skip the flour and butter. Instead, make a slurry by combining two tablespoons of cold water with 2 tablespoons of cornstarch; whisk it until thoroughly combined. Add the beef broth to the cooked mushrooms, then stir in the cornstarch slurry; continue to cook until sauce is thickened.
Nutritional info is an estimate and provided as courtesy. Values may vary according to the ingredients and tools used. Please use your preferred nutritional calculator for more detailed info.