Preheat oven to 425 degrees F.
Coat tenderloins with oil. Combine onion, garlic, citrus zest, salt, pepper and dried oregano in a pile on your cutting board. Pack this coating equally and evenly onto the tenderloins. Heat a large skillet. Add a drizzle of oil and sear tenderloin on all sides. Then place in hot oven to roast 20 to 25 minutes. Wash hands.
Brush rolls with a little warm water and sprinkle the tops of the rolls with 1/2 teaspoon sugar each. Pile rolls on a baking sheet and place in oven with meat for 5 minutes to crust rolls and set sugar. Authentic Cuban rolls used for this sandwich are sweet. This sugar wash process gives a similar effect to store bought rolls. When rolls come out of oven, split and pile on serving plate.
Preheat a stovetop griddle over medium high heat.
Heat 1/4 cup corn oil in a heavy skillet over medium high heat. Peel plantains and cut in 1/2 lengthwise, then slice each 1/2 into thirds on an angle. Arrange plantains in pan in a single layer and cook until crisp, continuously flipping for even browning. Remove from skillet to paper towel lined plate and season with fine salt.
To assemble sandwiches: Thinly slice meat on an angle. Place ham and Swiss cheese on a serving plate, separating and fluffing up the shaved meat and cheese. Assemble sandwiches with desired fillings and place on a hot, buttered griddle. Use a heavy pan to press the sandwiches together. Toast until golden brown, then flip and toast the other side.
Combine chopped pickles, sweet red pepper relish and scallions in a small bowl.
Spread the relish on the tops of the rolls and pork slices, ham, and swiss cheese on the bottoms. Press the sandwiches together. Put about 1 tablespoon of butter on the hot griddle and spread to coat. Put 2 sandwiches at a time on the griddle, and top with a heavy cast-iron skillet. Toast sandwiches on the griddle, turning once, until golden, hot, and cheese is melted, 2 or 3 minutes per side.
Serve with a few slices of plantains per person as a side dish. Frozen Mojitos Slushes make a great drink or dessert.
In a blender, combine 1/2 pint sorbet or 1/2 can of lime aid with 4 shots of rum, 1/4 cup mint leaves and 1/2 tray of ice. Pulse, then blend on high until lime-mint slush is smooth. Pour drinks into 2 large cocktail glasses using a long handled spoon and repeat with remaining ingredients.