First, marinate the mushrooms. Add mushrooms, olive oil, and Championship seasoning to a large bowl. Add Head Country marinade until mushrooms are covered, then toss to combine. Set aside.

Heating the butter in a medium skillet over medium heat, brown each bun, working in batches.

Shape beef into six patties. Dust each one, top and bottom, with Original Championship Marinade.

Heat grill to hot, or to 400 degrees F, spreading coals across the entire bottom of the grill. Add patties, close the lid on the grill, and cook, flipping every 5 or so minutes, until patties are close to desired doneness. (Internal temperature for a burger cooked medium is 145 degrees F.) Open the lid, add two slices of swiss to each patty, and close the lid again for 2-3 minutes, or until cheese is melted. Remove patties to a plate.

Add a large griddle or cast-iron skillet to grill grates. Add marinated mushrooms. Cook, stirring often, until mushrooms soften and begin to caramelize. Remove mushrooms to a bowl or plate. Toss with fresh parsley.

Assemble the burgers: bottom bun, cheese-covered patty, mushrooms, top bun. Enjoy!