Preheat oven to 200 °C or 180 °C fan. Line two baking rays with non-stick baking paper. Place the mince, onion, garlic, carrot, zucchini and hoisin sauce into a large bowl. Season with salt and pepper and use clean hands to thoroughly combine.
On a clean board, cut one pastry sheet in half. Lay 1/4 of the mixture along the centre of each piece and roll pastry over to enclose. Repeat with second pastry sheet. Brush rolls with beaten egg and sprinkle with sesame seeds. Cut each roll in half and place, seam side down, onto the prepared trays. Bake for 25 mins until golden brown.