Prepare the pork chops. Make a brine by combining the water, sugar, salt, thyme sprigs, clove and all-spice berries in a re-sealable bag. Add the pork chops, seal up the bag and put in the refrigerator for about 30 minutes.
Preheat oven to 425 degrees F.
Drain the pork chops and pat dry. Using a paring knife, make a horizontal cut into the center of each chop to make a pocket. Stuff a slice of fontina and prosciutto inside each pocket and secure with a toothpick. Set 2 large cast iron skillets over medium-high heat and add a 2-count of extra-virgin olive oil to each skillet. Add 2 chops to each of the skillets and cook for 4 to 5 minutes until golden. Turn chops, push to 1 side and set grape clusters in pan. Drizzle with a little olive oil and season with salt and pepper before putting the pans in the oven. Roast chops for 5 to 7 minutes until cooked through and cheese has melted. Remove from oven when done and set chops and clusters of roasted grapes aside on a plate - keep warm.
Consolidate juices into 1 pan and set over medium heat. Add a splash of chicken stock to the pan, scraping the bottom to extract all the flavors. Fold in cold butter while whisking to thicken sauce. Season with salt and pepper. To serve, set 1 pork chop on each plate on top of a Grilled Polenta Square, garnish with a cluster of roasted grapes and drizzle with pan sauce. Set a stack of hydroponic watercress to 1 side and serve.
Bring water and salt to a boil in a large saucepan. Gradually whisk in the cornmeal in a slow steady stream. Lower heat and continue to whisk until the polenta is thick and smooth, about 20 minutes. Add the cream and butter and continue to stir until incorporated. Remove from heat; fold in Parmesan and black pepper. Pour the polenta into a buttered 9 by 13-inch shallow baking dish and spread evenly with a spatula. Cover and chill a few hours. Cut the polenta into squares. Brush both sides with olive oil and transfer to a hot grill. Grill on both sides until golden brown.