Method

1. Preheat the oven to 200C/400F/Gas 6.

2. For the salmon en croute, mix the dill, chives, cream cheese and mustard together in a small bowl.

3. Slice the salmon in half across the middle and spread the cream cheese mixture on top of one of the halves. Place the other half fillet on top of the filling.

4. Roll the pastry out on a lightly floured surface to make a rectangle twice the size of the salmon fillet. Divide into two rectangles.

5. Place the salmon on top of one rectangle, making sure there's a 2½cm/1in border around the salmon. Brush the edges with beaten egg and place the second pastry rectangle on top of the fillet. Press down around the edges to seal and brush all over with beaten egg.

6. Place onto a baking sheet and bake in the oven for 12-15 minutes, or until the pastry is golden-brown and the salmon cooked through.

7. For the sauce, pour the cream and mustard into a pan and bring slowly to the boil. Season, to taste, with salt and freshly ground black pepper and stir in the dill.

8. For the sautéed spinach, heat the butter in a frying pan, add the spinach and stir until wilted.

9. To serve, place the salmon en croute onto a serving plate with the spinach and drizzle over the sauce.