Ingredients
2 x 550g/1¼lb pieces of skinned salmon fillet, taken from behind the gut cavity of a 3-4kg/7-9lb fish
100g/4oz unsalted butter, softened
4 pieces of stem ginger in syrup, well drained and finely diced
25g/1oz currants
½ tsp ground mace
750g/1½lb chilled puff pastry
1 egg, beaten, to glaze
salt and freshly ground black pepper

Method
1. Season the salmon fillet well with salt. Mix the softened butter with the stem ginger, currants, mace, ½ tsp of salt and black pepper. Spread the inner face of one salmon fillet evenly with the butter mixture and then lay the second fillet on top.
2. Cut the pastry in half and roll one piece on a lightly floured surface into a rectangle about 4cm/1½in bigger than the salmon all the way around - approximately 18 x 33cm/7 x 13in. Roll the second piece out into a rectangle 5cm/2in larger than the first one all the way round.
3. Lay the smaller rectangle of pastry on a well-floured baking sheet and place the salmon in the centre. Brush a wide band of beaten egg around the salmon and lay the second piece of pastry on top, taking care not to stretch it. Press the pastry tightly around the outside of the salmon, trying to ensure that you have not trapped in too much air, and then press the edges together well. Trim the edges of the pastry neatly to leave a 2.5cm/1 in band all the way around. Brush this once more with egg. Mark the edge with a fork and decorate the top with a fish scale effect by pressing an upturned teaspoon gently into the pastry, working in rows down the length of the parcel. Chill for at least an hour.
4. preheat the oven to 200C/400F/Gas6 and put a large baking sheet in it to heat up.
5. Remove the salmon en croute from the fridge and brush it all over with beaten egg. Take the hot baking sheet out of the oven and carefully slide the salmon parcel onto it. Return it to the oven and bake for 35-40 minutes. Leave it to rest for 5 minutes.
6. Transfer the salmon to a warmed serving plate and take it to the table whole. Cut it across into slices to serve.