Whole Salmon en Croûte with Watercress, Lemon & Dill Butter

⏱ 110 min · Serves 8

A glorious centrepiece: two salmon fillets sandwiching a vivid watercress, lemon and dill butter, wrapped in burnished all-butter puff pastry. Cut into thick slices to reveal a jade-green seam running through the pink fish — pure theatre, and surprisingly calm to make.

Per serving: 712 kcal · 42.0g protein · 33.0g carbs · 46.0g fat

Ingredients

• 2 x 700g skinless salmon fillets (a whole side split, or two centre-cut fillets of even thickness)
• 150g watercress, tough stems removed
• 100g soft unsalted butter
• 2 tbsp chopped dill
• 2 tbsp chopped flat-leaf parsley
• Zest of 2 lemons, juice of 1/2
• 2 tsp Dijon mustard
• 3 tbsp fresh white breadcrumbs
• 2 x 320g sheets all-butter puff pastry (or 650g block, rolled)
• 2 egg yolks, beaten with 1 tbsp milk
• Flaky sea salt and black pepper
• Plain flour, for dusting
• To serve: extra watercress, lemon wedges, 200ml crème fraîche mixed with 1 tbsp horseradish and 1 tbsp chopped dill

Method

1. Pat the salmon fillets very dry, season both sides generously with salt and pepper, and chill uncovered on a rack for 20 minutes — dry fish means crisp pastry.
2. Blanch the watercress for 20 seconds in boiling water, refresh in ice water, then squeeze bone dry in a clean tea towel. Chop finely.
3. Beat the watercress into the soft butter with the dill, parsley, lemon zest and juice, Dijon, breadcrumbs, a good pinch of salt and plenty of pepper. Chill 10 minutes until spreadable but firm.
4. Lay one salmon fillet on a board, spread the watercress butter thickly over it, then top with the second fillet, thick end to thin end so you get an even log. Tie loosely with string if it feels wobbly, and chill 15 minutes.
5. Lay one pastry sheet on a floured sheet of baking paper. Remove any string and sit the salmon in the centre. Brush the border with egg wash.
6. Drape the second pastry sheet over the top, easing it down the sides without stretching. Press out air, then seal the edges firmly and trim to a neat 2cm border. Crimp with a fork or fold and pinch.
7. Chill the whole parcel, on its paper, for 30 minutes (or up to 8 hours). Heat the oven to 200C fan / 220C / gas 7 with a heavy baking tray inside.
8. Brush all over with egg wash, score a fine diamond or fish-scale pattern into the top without cutting through, and sprinkle with flaky salt.
9. Slide the parcel on its paper onto the hot tray and bake 30–35 minutes until deeply golden and puffed; a skewer into the centre should come out warm, not hot (aim 48–52C for just-set salmon).
10. Rest 10 minutes, then cut into thick slices with a serrated knife. Serve with the horseradish crème fraîche, extra watercress and lemon wedges.