Preheat the oven to 200°C/400°F/gas 6.
Peel, core and dice the apple.
Pick off sage leaves.
Skin sausages and place the meat into a bowl.
Combine the pork, apple and sage leaves and in the bowl.
Season and set aside.
Roll out the pastry to 0.5cm thick and 34cm x 30cm. Halve lengthways and place a strip of mince down the centre of each.
Brush the edges with beaten egg, roll up and seal.
Brush with more egg, then cut into whatever size of sausage rolls you prefer.
Scatter tops with Nigella seeds for taste and decoration.
Score the tops (a few holes per sausage roll to let steam out) and bake for 20 minutes, or until golden and cooked through.