Turn the propane on, then ignite the burners to high heat. Brush the grates with a grill brush if necessary.

Close the lid and heat the grill until it reaches about 400 degrees. Reduce the heat to medium high, or about 375 degrees.

While the grill heats, form (4) 1/4 pound burger patties into an even 1/2″ thickness. Use your thumb to place a dimple in the center to prevent the burgers from shrinking. Season well with salt and pepper, to taste.

Close the lid and cook until the burgers reach the desired doneness. Rare: 2-3 minutes per side or 125-130 degrees, Medium: 3-4 minutes per side or 130-140 degrees, and Medium well 5-6 minutes per side, or 140-150 degrees.

Remove from heat and cover loosely with foil and allow to rest for 5 minutes.

Turn off the grill and place the buns split side down on the grill. Close the lid and toast for 2-3 minutes.

While the burgers cook, place the mayo, ketchup and pickle relish in a small bowl and stir to combine.

Assemble the burgers by placing lettuce down on the bottom half to prevent the bun from becoming soggy. Place the burger on top of the lettuce, and top with tomato and red onion. Spread 1 tablespoon of the sauce over the top half of the bun, and place over the burger. Serve immediately and enjoy!