Take pastry out of the fridge 20 minutes before use.
Preheat the oven to 220 C / Gas 7. The ready rolled puff pastry should come with baking paper, however if it doesn't, line a tray with baking parchment,
Cut the pastry in half. Spread out the sausage onto each pastry slice and push around in the centre. Lay egg slices, overlapping, on top of the sausage and season well. Repeat with remaining egg.
Carefully roll up pastry, seal edges with beaten egg or milk. Turn over. Score the top with a knife and brush all over top and sides with beaten egg or milk. Repeat and place onto a baking tray, allowing a sufficient gap.
Bake in the oven until golden and until the sausage is no longer pink at the centre, 35 to 40 minutes.