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 of fresh sage, leaves picked; 6 higher welfare pork sausages; 1 handful of breadcrumbs; fresh nutmeg, for grating; 250g ready-made puff pastry; 1 free-range egg; a little milk