Preheat oven to 200 degrees celsius (fan-forced).
Place the lamb mince, breadcrumbs, feta cheese (optional) and minced garlic into a large bowl.
Season with salt and pepper and mix well until combined.
Use a sharp knife to cut each pastry sheet down the middle (so that you have two long rectangles from each sheet).
Place one-sixth of the sausage roll mixture down the centre of each pastry half and roll to enclose. Place seamed side down.
Cut each roll into 3 equal pieces.
Place the rolls onto 2 baking trays lined with baking paper.
Brush the pastry lightly with the whisked egg and sprinkle with poppy seeds or sesame seeds.
Cook for 20 minutes or until golden and crispy.