For the brine: Mix the salt and sugar in 6 cups cold water until dissolved. Pour the brining liquid into a one gallon zipper-topped bag and place the pork in the brining liquid. Place the bag in a large bowl to prevent leakage, and keep in the fridge for 1 hour.
For the pork: After 1 hour, remove the pork and dry off with paper towels. Cut into 1-inch medallions, making about 8 medallions. Gently pound each medallion with a meat mallet until the pork is about 1/4-inch thick. Sprinkle with pepper and set aside.
Set a wire rack inside a baking sheet. Set up a standard breading procedure in three shallow pie tins. Put the flour in one, the beaten egg in another and the panko in the last one. Dredge each medallion in the flour, shake off any excess, then in the egg, let the excess drip and then coat fully in the breadcrumbs. Set aside the wire rack.
Preheat the oven to 175 degrees F. Heat up the oil in a heavy-bottomed skillet to medium heat.
Place half of the medallions in the oil and fry on each side until golden brown, 3 to 4 minutes a side. Set the cooked medallions aside on another wire rack and place in the oven to stay warm. Repeat with the remaining medallions.
For the sandwich build: Carefully split the Grapevine KY Buttermilk Biscuits and lay a medallion or 2 on the bottom portion. Slather the biscuit tops with Raspberry Mayo and then top with some Cider-Braised Red Cabbage. Serve any remaining cabbage on the side.
Grapevine KY Buttermilk Biscuits:
Preheat the oven to 425 degrees F. Place heavy cast-iron skillet into oven to preheat. Chill a large mixing bowl, pastry cutter, flour and 1 stick butter in the freezer 15 minutes before assembling the biscuits.
Add the flour to the chilled mixing bowl. Working quickly, cut 1 stick butter into the flour using the chilled pastry cutter (or your fingers); the goal here is pea-size balls of butter. In batches, add in the buttermilk until the dough is cohesive yet still moist. Turn the dough out onto a floured surface and lightly press into a 1-inch-thick round. Using a biscuit cutter or business end of a dry-measuring cup, cut out 8 biscuits. (Use the extra dough to cook up a big piece of shortcake for dessert....strawberry shortcake!)
Carefully remove the skillet from the oven and add the oil. Place the dough rounds into the hot skillet, right up against each other, and brush with the 3 tablespoons melted butter. Bake until golden brown, about 15 minutes.
Mix the mayo, lemon juice, raspberry preserves, lemon zest and pepper in a bowl.
Cider-Braised Red Cabbage:
Heat a heavy-bottomed Dutch oven over medium heat. Add the butter until melted. Add the caraway seeds and stir until fragrant, about 30 seconds. Add the cabbage in batches until slightly wilted, 5 minutes. Add the cider and vinegar and simmer for 15 minutes until the cabbage is soft and supple. Season with salt and pepper.