Next time you have leftover meringue, plop it or pipe it onto parchment paper, place the meringues in a slow oven, 200f-250f, for an hour, turn the oven off, don’t open the door, let them continue drying for several hours or overnight. If the gods are with you the meringues should be dry and crisp.I had mountains of it!) I made two thirds of the recipe and still ended up throwing half of it away. Deeply frustrating and wasteful.)
If the meringues are small you can sandwich them with jam or melted chocolate after they cool.