In a large bowl, mix beef, pork, onion, garlic, jalapeño, egg, Capatriti® Extra Virgin Olive Oil, salt, and pepper. Form thin patties, each approximately ¼-inch thick. Stack patties, layering wax paper in between.
In a cast iron skillet, over medium heat, cook patties two at a time, approximately 5 minutes per side. After the first flip, add slice of cheese to each patty, and let cook for 2 minutes before stacking patties in the skillet.
Meanwhile, spread mayonnaise on the bottom of the bun and layer with lettuce. Place cheesy patties on top and add a dollop of ketchup. Then layer tomato slice and two pickles. Spread mustard on the top of potato bun. Share.