Salmon En Croute with Wild Garlic

1. Put a pan of water onto to boil. When it's bubbling, add the baby leaf spinach and wild garlic. Simmer for 30 secs. Drain well through a colander, rinse under cold water then set aside to cool for 10 mins. When the spinach and wild garlic are cool enough to handle, squeeze as much excess water out of them as posible. You can pop them in a clean tea towel, wrap that around them and then wring it to help squeeze out the water (this may stain your tea towel green, so wash it straight away).

2. Roughly chop the spinach and wild garlic. Scoop them into a bowl. Finely grate in the zest from the lemon, then grate in ¼ nutmeg. Add the crème fraîche and season with salt and pepper. Stir to mix. It should be thick and creamy.

3. Slice the salmon fillet in half to create two 400g fillets. Pat dry with kitchen paper. Slide a sharp knife the under the skin and run along the fillet to remove the skin. Run your fingers over the fillets to check for any pin bones and remove them with tweezers if you find any.

4. Place one fillet, skinned-side down, on your work surface. Spread the spinach and wild garlic mixture over the top. Top with the remaining fillet, skinned-side up.

5. Line a large baking tray with baking paper. Dust your work surface with flour and roll 1 block of pastry out to make a 30cm x 25cm rectangle. Roll the pastry around your rolling pin, then unroll it on the baking tray. Brush 1-2 tbsp horseradish relish over the pastry, leaving a 2cm border around the edge. Place the salmon fillets on the pastry, covering the horseradish. Crack the egg into a bowl, beat it, then brush the pastry border with beaten egg.

6. Dust your work surface with a little more flour and roll out the second block of pastry. Lay it over the top of the salmon and crimp the pastry edges together with a fork. Press a tablespoon lightly all over the top of the pastry to make 'scales'. Chill in the fridge for 30 mins-4 hrs.

7. Preheat your oven to 180°C/Fan 160°C/Gas 4. Take the salmon out of the fridge and poke a few small holes in the pastry to let the steam escape. Brush the top of the pastry with the remaining beaten egg to glaze. Bake the salmon en croute for 40 mins till golden brown. If you have a meat thermometer, you can slide it into the middle of the pie to check the temperature. The salmon is cooked through when it hits 63°C.

8. Let the salmon en croute rest for 5 mins. Serve in slices with your favourite side dishes.