Place two buttered bread slices (buttered side down) in skillet. Place 1-2 slices of cheddar, provolone, and tomato, along with pinch of salt and pepper, on top of bread, and top with remaining buttered sourdough.
How to reheat: I recommend reheating it in the toaster oven (or regular oven) to help re-crisp the bread. Place it in a 350 degree F oven for around 10 minutes. Reheating in the microwave may lead to soggy bread.