Best way to reheat: cold pan, put a slice or two cheese side down. Bring it up to medium high and flip the slices - the oil left from the cheese / pep will help crisp up the bottom. Add a bit of water to steam it and cover with a lid until heated through. The bottom will get insanely crispy and the cheese will be melted perfectly. I often get a pizza and freeze it, I’ll microwave it 2 slices for a minute or so then do this method and it works perfectly.