In a large bowl, gently mix the ground beef, Worcestershire sauce, seasoning salt, and beaten egg. Avoid overmixing.
Shape the beef mixture into 4 patties and refrigerate them while you prepare the other ingredients.
Melt butter in a large skillet over medium-high heat.
Add the sliced onions to the skillet and sauté for 3-4 minutes, stirring occasionally.
Stir in the sliced mushrooms, season with salt and pepper, and sauté for an additional 3-4 minutes until soft and slightly browned. Transfer the mixture to a plate.
Brown each side of the beef patties in the skillet for 2-3 minutes per side.
Place the browned patties in a baking dish and top each with the mushroom and onion mixture.
Bake for 8-10 minutes until the patties are fully cooked.
Sprinkle the shredded Monterey Jack Cheese over each patty and bake for an additional 1-2 minutes until the cheese melts.
Remove from the oven, serve warm, and savor the delicious flavors!
Notes
No alcoholic drinks allowed, please substitute with a non-alcoholic option.