Chicken sausages are used here rather than chicken mince because they bring built-in seasoning and fat, which helps keep the filling flavourful and prevents it becoming dry once baked in pastry. Chicken mince can be used instea, but you may need to add extra seasoning and a small splash of stock to maintain moisture. Pork or turkey sausages also work well. Sage and onion stuffing can be swapped for plain stuffing with a pinch of dried sage added. Reduced-fat puff pastry can be replaced with standard puff pastry if preferred.