Ofen vorheizen auf 200°C and line a baking tray with baking paper.
Remove the boerewors from its casing and break it up into a mince-like texture.
(Optional) Mix in onion, garlic powder, salt, and pepper for extra flavour.
Roll out the puff pastry and cut into 2–3 long strips.
Place a line of boerewors mixture down the centre of each strip.
Roll the pastry over the filling and seal the edge with a little water.
Cut into smaller rolls (bite-size or full size).
Place on tray, seam side down.
Beat egg with a little milk and brush over the tops.
Sprinkle with seeds if using.
Backen für 20–25 minutes until golden and crispy.