Ingredients:
3oz (85g) watercress, coarse stems removed
1⁄2 cup cream cheese
sea salt and freshly ground black pepper
1lb 5oz (600g) skinless salmon fillet
14oz (400g) ready-made puff pastry
all-purpose flour, for dusting
unsalted butter, for greasing
beaten egg or milk, for glazing

Method
1 Preheat the oven to 400°F (200°C). Chop the watercress very finely, place in a bowl, add the cream cheese, season with salt and pepper, and mix well.

2 Cut the salmon fillet into 2 pieces. Roll out the pastry on a lightly floured surface to a thickness of 1⁄8in (3mm). It should be roughly 3in (7.5cm) longer than the salmon pieces and just over twice as wide. Trim the edges straight. Transfer to a lightly greased baking sheet.

3 Place 1 piece of salmon in the middle of the pastry. Spread the top with the watercress cream and place the other piece of salmon on top. Lightly brush the pastry edges with water, then fold both ends over the salmon. Fold in the sides so they overlap slightly and press together to seal. Re-roll the trimmings and use to decorate the top of the pastry, if liked. Brush with the beaten egg, and make 2 or 3 holes with a skewer to allow steam to escape.

4 Bake for 30 minutes, or until the pastry is well risen and golden brown. Test if the salmon is cooked by pushing a skewer halfway through the thickest part and leaving it for 4–5 seconds; when removed, it should feel hot.

5 Remove from the oven and allow to stand for a few minutes, then slice and serve.

PREPARE AHEAD:
The whole dish can be made up to 12 hours before baking. Cover with plastic wrap and chill until ready to cook.

Salmon En Croute