In a large bowl, combine ground beef, breadcrumbs, egg, salt, pepper, onion powder, and garlic powder.
Shape the mixture into four oval patties, approximately 3/4-inch thick.
Heat vegetable oil in a large skillet over medium-high heat.
Sear patties for 3-4 minutes per side until browned, then remove from skillet and set aside.
In the same skillet, melt butter and add sliced onions. Cook until softened and translucent, about 5 minutes.
Sprinkle flour over the onions and stir for 1-2 minutes to create a roux.
Gradually whisk in beef broth and Worcestershire sauce, scraping the bottom of the pan to release browned bits.
Bring gravy to a simmer and return patties to the skillet.
Lower heat and simmer for 5-8 minutes until the gravy thickens and patties reach an internal temperature of 160°F (71°C).