Form beef into four patties. Season with your favorite rub.
Preheat grill with cast iron insert on high heat.
When pan is hot, cook burgers for about 4 minutes per side,flipping once, until cooked to your preferred doneness. I cook mine to medium-about 145° internal temperature. Top with cheese until just melted.
Meanwhile, place pulled pork on griddle and heat through. Toast buns until golden brown.
Assemble the burgers by layering two burger patties on a bun, topped with two bacon slices, two onion rings, and a handful of heated pulled pork.
Top generously with Head Country Hickory Smoke BBQ sauce and top bun.