In a large bowl, combine ground beef, breadcrumbs, egg, Worcestershire sauce, garlic powder, onion powder, salt, and pepper. Mix until well combined. Form into four equal patties.
Heat olive oil in a large skillet over medium-high heat. Add the patties and cook for 3-4 minutes on each side until browned. Remove and set aside.
In the same skillet, add the sliced onion and sauté until caramelized, about 8-10 minutes.
Sprinkle flour over the onions and stir for 1 minute. Gradually pour in beef broth, whisking to prevent lumps. Simmer for 3-5 minutes until the gravy thickens.
Stir in butter and fresh thyme (if using). Return the patties to the skillet, spooning gravy over them.
