Spread a thin layer of mustard onto cut side of bottom half of roll. Layer with 1 cheese quarter, 1 ham slice, another cheese quarter, about ½ ounce smoked pork, another cheese quarter, 2 pickle slices, and top of roll. Secure with a wooden pick. Repeat with remaining rolls.
In a 10-inch cast-iron skillet, melt butter over medium heat, swirling to coat. Reduce heat to low. Place one sandwich in center of skillet. Closely fit remaining sandwiches in skillet. Lightly spray top of sandwiches with cooking spray. Remove wooden picks. Heat another 10-inch cast-iron skillet over medium-low heat until warm. (Do not overheat.) Place on top of sandwiches.
Bake until sandwiches are heated through and cheese is melted, 8 to 10 minutes.
Recipe by Southern Cast Iron at https://southerncastiron.com/pressed-cuban-sliders/