Prepare the Sauce: In a small bowl, mix together mayonnaise, ketchup, mustard, pickle relish, garlic powder, onion powder, and a pinch of salt until well combined. Cover and refrigerate until you’re ready to indulge.

Caramelize Onions: Melt butter in a skillet over medium heat. Add the thinly sliced onions and cook, stirring often, for about 15 minutes until they’re deeply golden and wonderfully soft. Set them aside.

Season the Beef: In a large bowl, combine ground beef with salt, black pepper, garlic powder, onion powder, and Worcestershire sauce. Gently mix and divide into 4 equal portions, forming wide patties.

Sear the Patties: Heat a large skillet over medium-high heat and lightly coat it with cooking spray. Sear each patty for 3 to 4 minutes on each side until browned and cooked through. Set aside.

Assemble the Sandwiches: Lay out 8 slices of rye bread. Spread signature sauce on 4 slices. Layer cheese, the patty, caramelized onions, and top with the remaining slices.

Grill to Perfection: Melt butter in a skillet over medium heat. Grill each sandwich for 3 to 4 minutes on each side while pressing gently with a spatula until golden brown.

Serve and Enjoy: Cut each sandwich in half and serve hot with extra signature sauce on the side for dipping.