Preheat the oven to 180 C. Line a baking tray with grease-proof paper. Remove the pastry from the freezer, and set aside.
Add chickpeas, grated veg, onion and garlic to a food processor, and blitz for 30-40 seconds.
Transfer to a large bowl, and cover. Place in the fridge for 15 minutes to set.
Meanwhile, roll out the pastry and cut down the middle into two long rectangular strips.
Spread half the chickpea mix into a sausage shape over one half of the pastry. Roll the pastry over on itself. Using a fork, pinch the corners together to seal.*
Brush with the beaten egg and cut each roll into eight pieces. Transfer to the lined tray and bake for 20-30 minutes until golden, crispy and cooked through. Serve warm.
*If freezing, cut each roll into 8 mini rolls and place in the freezer here.