Cut the dough in half and roll out the dough. You should have 2 flatbreads to work with.
Add 2 tbsp of pesto to each of the doughs. Using the back of a spoon, spread the pesto to create a thin layer of pesto as the "pizza sauce".
Add 8 slices of mozzarella around the dough. Do not overlap the cheese, it should have some space in between each of the cheese slices.
Add the sundried tomatoes around the flatbreads. Put them on the pesto, not on the cheese slices.
Bake the flatbread at 450 degrees F for 7-12 minutes. The flatbread edges will be light-golden brown, and the cheese will start browning when it's ready to come out of the oven.
Remove the flatbread from the oven and place it on a wooden cutting board.
Using a spoon, spoon the pesto onto the flatbread. While it's still warm, the pesto will melt into the pizza. This is a crucial step, and cannot be missed. Having the extra fresh pesto on the flatbread will make the pesto have more sauce, and will prevent it from being dry. Fresh pesto adds a ton of flavor to flatbread.
Cut and serve immediately.
Store in the refrigerator for up to 3 days.