Pulse lard, salt, and flour in a food processor until breadcrumbs form.
Add 180ml cold water while pulsing until a dough forms.
Wrap dough in cling film and chill for 20 minutes.
Soften shallots in oil over low heat for 8 minutes.
Brown chicken livers in butter with the shallots and season.
Fry with sage and garlic for 5 minutes then cool completely.
Mix duck and chicken mince with 50ml water until combined.
Fold in chopped cooled livers and parsley and season well.
Shape the stuffing mixture into a large sausage.
Preheat the oven to 170°C.
Place stuffing inside the boned duck and roll into a ballotine.
Secure the duck with skewers or string.
Roast duck in a tray with oil for 20 minutes.
Baste the duck and roast for another 15 minutes.
Drain and reserve 200ml of roasting juices for the sauce.
Increase oven temperature to 200°C.
Roll out pastry and brush with egg wash.
Wrap the duck in pastry and seal the edges by crimping.
Bake on a lined tray for 30 minutes until golden-brown.
Boil port, wine, juices, and shallot until reduced by half.
Add 300g blackberries and boil until the liquid reduces by half again.
Stir in remaining 100g halved blackberries and serve with sliced pie.