1 large unwaxed lemon, juice and finely grated zest
1 large onion, finely chopped
3 tbsp chopped fresh parsley
1 tbsp chopped fresh sage
salt and freshly ground black pepper
150g/5陆oz fresh white breadcrumbs
1 tbsp vegetable oil
40驳/1陆辞锄 butter, plus extra for greasing
700g/1lb 9oz pork sausage meat