Sausage rolls

Name: Sausage rolls
Cook time: 1 h 5 min
Total time: 1 h 5 min
Cuisine: British
Ingredients: olive oil; 1 red onion peeled and finely sliced; 1 sprig fresh sage leaves picked; 6 higher-welfare pork sausages; 1 handful breadcrumbs; fresh nutmeg for grating; 250 g ready-made puff pastry; 1 free-range egg; a little milk