1. Preheat the oven to 200°C fan-forced.
2. Remove pastry from the freezer and leave out to thaw until soft enough to handle.
3. Dust your bench top with buckwheat flour and roll out your pastry sheet.
4. Cut your pastry sheet in half.
5. Spoon 2 tablespoons of pesto onto each half of the pastry and use the back of spoon to spread the pesto over the pastry.
6. Top with tomatoes, zucchini, basil leaves and parmesan and fold over the sides, leaving an open top.
7. Brush each side of the pastry with egg wash.
8. Place in the oven to bake for 20 minutes or until the pastry is golden.