CHEF'S NOTES:
You can make strawberry slices a day ahead. I have made them on a silpat and on parchment. A few stuck on the parchment and had to be carefully peeled off, but it wasn't catastrophic. That being said, they didn't stick at all on the silpat.
Make sure the strawberries for the frosting are FREEZE DRIED. Not "dried" fruit, like raisins or dried cranberries. This will not work.