You sure can! When you make the sandwiches, assemble as you would normally, and then tightly wrap each sandwich in parchment paper and place it in a ziplock bag or airtight container. Store in the freezer or in the refrigerator. When you are ready to reheat them, remove them from the freezer or refrigerator, remove them from a ziplock bag or container, and microwave until warm. I prefer to microwave them while still in the parchment paper, which is why I don't recommend storing them in foil-foil can't be microwaved.