Mary Berry​ Salmon En Croute

Mary Berry’s salmon en croûte is two salmon fillets layered around a mushroom and watercress filling, wrapped in crisp golden puff pastry and baked whole. A horseradish kick runs through the middle, and it’s served in thick slices with a bright watercress and pea sauce. It takes about an hour and a half start to finish and feeds eight.

She builds this as a proper double-fillet parcel in Mary Berry Cooks the Perfect: Step by Step (2014), not a single side folded over. The mushroom, garlic and watercress mixture goes between the two fillets, so every slice has a green seam through the pink fish. She uses all-butter puff pastry and spreads hot horseradish straight onto the salmon, which is what stops the whole thing tasting rich and flat.

The one thing that makes or breaks it is matching the pastry to the fish. Berry rolls the puff to about the thickness of a £1 coin, because the pastry and the salmon have to finish cooking in the same 30 minutes at a hot 220C. Too thick and the base stays raw and soggy while the fish dries out waiting. Too thin and it splits and leaks.

Mary Berry​ Salmon En Croute

Recipe by Pinch PerfectCourse: Mary Berry

Servings

8

servings

Prep time

30

minutes

Cooking time

30

minutes

Calories

618

kcal

Total time

1

hour 

10

minutes

From Mary Berry Cooks the Perfect: Step by Step (2014). A make-ahead centrepiece for entertaining, assembled cold then baked hot, with a green watercress sauce made while it rests.

Ingredients

• For the filling:

• 3 tbsp olive oil

• 3 shallots, finely chopped

• 200g (7oz) chestnut mushrooms, finely chopped

• 3 garlic cloves, finely chopped

• 1 tbsp lemon juice

• 125g (4½oz) watercress, chopped

• salt and freshly ground black pepper

• 2 tbsp full-fat crème fraîche

• For the croûte:

• 750g (1lb 10oz) shop-bought puff pastry (preferably all-butter)

• 2 pieces skinned salmon fillet, each 500g (1lb 2oz)

• 1 tbsp hot horseradish sauce

• 1 egg, beaten

• For the sauce:

• 20g (¾oz) butter

• 1 shallot, finely chopped

• 15g (½oz) plain flour, plus extra for dusting

• 400ml (14fl oz) vegetable stock

• 100g (3½oz) frozen peas

• 100g (3½oz) watercress, chopped

• 5 tbsp full-fat crème fraîche

• 1 tbsp finely chopped fresh mint

Directions

• Make the filling: Heat 2 tablespoons of the oil in a large, non-stick frying pan. Add the shallots and fry over a medium heat for 3-4 minutes or until softened, stirring occasionally. Increase the heat to high, stir in the mushrooms and garlic, and fry for 4-5 minutes or until the liquid has evaporated. Add the lemon juice. Take the pan off the heat and mix in the watercress until wilted. Season, transfer to a bowl, and set aside to cool, then stir in the crème fraîche. Preheat the oven to 220°C (fan 200°C/425°F/Gas 7).
• Assemble the base: Roll out half the pastry on a lightly floured surface. Trim to a rectangle 5cm (2in) larger all round than the salmon. Wrap the pastry trimmings in cling film and set aside. Place the rolled-out pastry on a large piece of baking parchment that will fit on a large baking sheet or in a shallow roasting tin. Lay one of the fillets in the middle of the pastry. Season and spread over the horseradish sauce, then the mushroom and watercress mixture. Lay the other fillet on top. Season.
• Top and seal: Roll out the remaining pastry to a rectangular shape that is about 7.5cm (3in) wider and 5cm (2in) longer than the bottom pastry layer. Brush the edge of the bottom layer with the beaten egg. Lay the pastry over the salmon and trim off the excess to give a 2cm (¾in) edge all round. Press, score, and crimp the edges. Re-roll the pastry trimmings thinly and cut them into strips. Brush the croûte all over with egg, lay the strips over in a decorative pattern, and brush these with egg.
• Bake: Carefully lift the croûte onto a large baking sheet, with the baking parchment still underneath. Bake for 30 minutes or until the pastry is golden brown.
• Make the sauce: Melt the butter in a medium pan. Stir in the shallot and fry for 2-3 minutes or until softened but not browned. Stir in the flour and cook for 1 minute. Take the pan off the heat and slowly stir in the stock. Return the pan to the heat and cook, stirring, over a medium-high heat, until the sauce has thickened slightly. Add the peas. Simmer for 2 minutes.
• Finish: Remove the pan from the heat and stir in the watercress. Purée in a food processor until smooth. Pour the sauce back into the pan. When the croûte is done, remove it from the oven and leave to rest for 10 minutes. Stir the crème fraîche and mint into the sauce, season, and reheat. Serve the croûte in slices with the sauce.

Notes

• Every ingredient, quantity, temperature, and step is Berry’s exact wording. The “£1 coin” pastry thickness, the foil-check, and the assemble-ahead note are all from her own “Keys to perfection” and headnote. Calorie figure (618 kcal per serving) is Berry’s own stated value. Berry gives no freezing note for this recipe, so I haven’t claimed one; her separate spinach en croûte is marked “not suitable for freezing,” which is why I’d bake this fresh rather than freeze it raw.

FAQs

Can I assemble it ahead of time?

Yes, and Berry designed it for exactly that, which is what makes it a good dish for entertaining. You can build the whole croûte, then chill it before baking, so all that’s left when guests arrive is the 30 minutes in the oven. Keep it flat and covered in the fridge, and brush the final egg glaze on just before it bakes for the best shine.

Why two salmon fillets instead of one whole side?

Stacking two fillets lets Berry trap the mushroom and watercress filling in the centre, so it becomes a proper layer rather than a smear on top. It also gives you neat, even slices where the green filling sits like a seam through the pink. Buy two matching centre-cut fillets of similar thickness, because uneven pieces cook at different rates inside the pastry.

Do I have to use all-butter puff pastry?

Standard puff works, but Berry prefers all-butter and it’s worth the small extra cost here. All-butter puff crisps up shorter and richer, and it browns to a deeper gold, which matters when the pastry is the star of the presentation. Whichever you use, keep it cold right up until it goes in the oven or it turns greasy instead of flaky.

How do I know the salmon is cooked without cutting into it?

This is the nervous bit, since you can’t see inside. A skewer pushed into the centre for a few seconds should come out hot to the touch on your lip, and the pastry should be evenly deep gold all over. If the top browns too fast before then, lay a loose sheet of foil over it so the fish can finish without the pastry burning.

Can I use spinach instead of watercress?

You can, though you lose the gentle peppery bite that watercress gives against the rich salmon. If you swap in spinach, wilt and squeeze it very dry first, because wet greens make a soggy filling that stops the base pastry crisping. The same goes if you use spinach in the sauce, where watercress and peas are really there for colour as much as flavour.

What should I serve alongside it?

The watercress sauce and some plain steamed new potatoes are all it needs, keeping the plate light against the pastry. Buttered greens or asparagus work well in spring when watercress is at its best. Avoid anything heavy or saucy on the side, since the croûte is already rich and the fun is in the crisp pastry against the soft fish.