Combine the yogurt, thyme, and salt and pepper. Spread the yogurt mixture on both sides of the flounder fillets. Season the cornmeal with creole spice. Dredge the flounder in the cornmeal. Heat 1/4 cup of oil in a skillet. Place the crusted flounder into the hot oil. Cook for 3 minutes on each side Drain the fish on a paper towel. Serve the flounder on a plate, topped with the oyster relish. Garnish with parsley.