Season steaks on both sides with garlic pepper. Heat large nonstick skillet over medium-high heat; melt butter and cook pork quickly, browning nicely on both sides, about 4-5 minutes on each side. Serve steaks in buns topped with some Caramelized Onions and slice of cheese.
*Caramelized Onions: Thinly slice 4 cups yellow onions; heat two teaspoons each butter and olive oil in large skillet; add onions and one tablespoon sugar and cook slowly over medium-low heat, stirring occasionally, until onions are a rich golden brown, about 25 minutes. Onions can be made ahead of time, covered and refrigerated for 2-3 days. Reheat in microwave or reheat gently in skillet.