Preheat oven to 220°C/425°F. Cut six rectangles from each of 2 sheets ready-rolled puff pastry. Spread ½ cup harissa paste evenly on the 12 pastry rectangles.

Place one sausage on each pastry rectangle, roll up pastry to enclose, brush ends with beaten egg to seal. Place seam-side-down on baking-paper-lined oven trays. Brush pastry with egg, cut slits in tops of rolls, sprinkle with dukkah. Bake rolls for 30 minutes or until cooked through.