Preheat the oven to 200C fan and line a baking tray. Squeeze the grated apple in a clean tea towel to remove excess juice.
Mix the sausage meat, apple, Cheddar, wholegrain mustard, sage and a generous grind of pepper.
Unroll the pastry and cut lengthways into two equal strips. Shape half the filling into a log down the centre of each.
Brush one long edge of each strip with beaten egg. Roll the pastry around the filling and place seam-side down.
Cut each log into six pieces. Arrange on the tray, brush with egg and scatter with sesame seeds.
Bake 25-30 minutes until puffed, deeply golden and cooked through.
Cool at least 10 minutes before serving. Also excellent at room temperature.
Tap to reveal the secret seasoningWholegrain mustard – it gives the apple and Cheddar filling enough sharpness to cut through the rich sausage meat and buttery pastry.