Mozzarella, cheddar, or blue cheese — you decide. These are a great snack and a full meal with a salad. The recipe uses sous vide beef, so it will be tender, but the tomatoes need a bit of a fry prior to adding to the stack so it all gets done at the same time. These are good cold, so they could be great on a buffet, cut into quarters with a toothpick, as posh sliders.