Preheat the oven to 200°C.
Roll out the puff pastry on a floured surface to 30x20cm.
Remove sausage skins and spread meat over the pastry, leaving a small border.
Scatter fennel seeds over the meat and season with salt and pepper.
Brush the pastry edges with beaten egg.
Roll both short sides inward to the center and brush with egg wash.
Cut the roll into 8-10 slices and place flat on a baking tray.
Brush slices with egg and bake for 10-15 minutes until golden.
Boil chopped apple and apple juice in a pan until soft.
Mash the softened apples with a fork or masher.
Add the cardamom seeds to the sauce.
Serve the warm pastries with the apple sauce.