For extra crisp edges, bake the flatbread on the lower third rack of the oven and roll it slightly thinner. The dough is easiest to work with when the cheese is still warm; if it becomes too stiff, briefly warm it again in the microwave and knead until smooth. Leftovers keep well in an airtight container in the refrigerator for up to 3 days or can be frozen for up to 2 months, then reheated in a hot oven or dry skillet until warmed through and slightly crisp.