Sausage Rolls

Pastry

• 8 oz all-purpose flour, plus extra to dust
• 6 oz unsalted butter, in pieces, frozen
• ⅛ tsp salt
• 2 ½ oz ice water

Sausage Filling

• 4 oz yellow onions, quartered
• 16 oz ground pork sausage, crumbled
  ou 16 oz uncooked pork breakfast sausages, casings removed, crumbled or cut into pieces
• 1 tsp mixed dried herbs
• ½ tsp salt, to taste
• ⅛ tsp ground black pepper
• 1 large egg, whisked, to brush