Preheat oven to 200°C (180°C for fan assisted ovens)/Gas M6
Cut the vegetables into evenly sized chunks & lay on a baking sheet along with the sprigs of rosemary. Drizzle lightly with olive oil and place into a preheated oven to cook until just tender approximately 20-30 minutes. Allow to cool.
Unroll the pastry sheet and cut into 4. Spread each quarter with the pesto leaving a 2-3cm boarder all the way around.
Scatter the cooled roasted vegetables over the pesto. Brush pastry boarder with beaten egg and fold up the edges to contain the filling. Place in a preheated oven for 15- 18 minutes until border is golden brown. Serve immediately.