Lay out slices of bread. Coat each slice with Epicurean White Truffle Butter. Turn the slices over and places slices of Gruyere cheese on 4 slices of the unbuttered side of bread. Place the non buttered side of bread over the cheese.
Heat a cast iron skillet over medium high heat. Place the sandwiches buttered side down in the hot skillet. Cook until nice and golden brown. Checking it every 30 seconds with a spatula by lifting the corner of each sandwich. When golden brown, flip the sandwiches and cook until done.