1 small yellow onion, grated
2 tablespoons Worcestershire sauce (eyeball it)
3 tablespoons tomato paste
2 tablespoons hot sauce
Steak seasoning (preferred brand McCormick Montreal Steak Seasoning)
Extra-virgin olive oil (EVOO), for drizzling plus 1 tablespoon
8 pieces of Texas sourdough toast (thickly sliced bread)
4 slices pepper jack cheese
4 slices cheddar cheese
Preheat grill, grill pan or large non-stick skillet.
Combine the meat with the grated onion, Worcestershire sauce, tomato paste, hot sauce and steak seasoning. Form four large patties and drizzle each with a touch of EVOO. Grill 4-5 minutes on each side and reserve until ready to assemble.
Place the cheddar cheese on the bottom piece of bread, top it with the cooked burger and place the pepper jack cheese on top of that. Cover with the remaining piece of bread and put back on the grill pan to melt the cheeses and toast the bread. Cover the sandwiches loosely with a sheet of tin foil and continue cooking until cheese is melted. Serve with thick-cut French fries and mixed green salad.