In a large mixing bowl, combine ground beef with Worcestershire sauce, seasoning salt, garlic powder, and black pepper. Gently mix and form into 1-inch thick patties.

Heat a skillet over medium heat. Cook the patties for about 3-5 minutes per side until nicely seared. Transfer to a plate lined with paper towels.

In a medium bowl, whisk together beef stock, soy sauce, Worcestershire sauce, ketchup, and cornstarch until smooth. Melt butter in the skillet, sauté onions and mushrooms if desired, then add the gravy mixture and stir until thickened.

In a non-stick pan, melt a tablespoon of butter over low heat. Crack the egg and fry sunny-side up for 3-4 minutes.

On a plate, place a scoop of rice, top with a cooked patty, ladle gravy over it, and finish with the fried egg. Garnish with green onions.