01 -
Combine ground chuck, Worcestershire sauce, seasoned salt, and black pepper in a medium bowl; mix thoroughly until well combined.
02 -
Form the mixture into four oblong patties approximately 1.25 cm (1/2 inch) thick each.
03 -
Melt butter in a medium skillet over medium-low heat; add sliced onions with a pinch of salt and sauté for 3 to 4 minutes, stirring occasionally.
04 -
Add sliced mushrooms to the skillet and continue sautéing for an additional 3 to 4 minutes until mushrooms begin to brown; remove from heat.
05 -
Heat a large cast-iron or stainless-steel skillet over medium heat; cook patties for 4 to 5 minutes on one side, flip, and cook for 3 to 4 minutes on the other side.
06 -
Top each patty with sautéed onions, mushrooms, and shredded Monterey Jack cheese; turn off the heat and allow cheese to melt before serving.