In a large bowl mix together ground beef, egg, breadcrumbs, salt, pepper, onion powder, garlic powder and Worcestershire.
Form the meat mixture into 4 balls, then flatten into patties. Set aside.
In a medium bowl mix together water, sherry, corn starch and gravy packet. Set aside.
Heat olive oil into a large skillet over medium heat, add the onions and saute until wilted, or desired texture. Remove and set aside.
In the same skillet, add patties and cook for 3-4 minutes for each side until cooked through to desired temperature. Remove and set aside.
Add the gravy mixture to the skillet and simmer, stirring constantly until it is thick.
Add the patties and the onions back to the skillet and cover the patties with the onion & gravy mixture. Allow to cook for 3-5 minutes.
Plate and Serve alone or with mashed potatoes or white rice.