Equipment
Ingredients
Potato Topping
- 1000 g floury potatoes, peeled and cut into even chunks
- 50 g unsalted butter, cubed
- 50 ml whole milk, warmed
- 2 egg yolks
Poaching Base
- 600 ml whole milk
- 300 g skinless cod fillet, cut into large chunks
- 200 g skinless smoked haddock, cut into large chunks
- 200 g skinless salmon fillet, cut into large chunks
Sauce and Filling
- 50 g unsalted butter
- 150 g leek, trimmed, washed thoroughly, and finely sliced
- 50 g plain flour
- 150 g raw king prawns, peeled and deveined
- 100 g frozen peas
- 10 g fresh dill, finely chopped
- 10 g dijon mustard
- 1 lemon, zested and juiced
Nutrition (per serving)
Method
Place the prepared potatoes in a large saucepan, cover with cold salted water, and bring to a boil. Simmer for 15 to 20 minutes until tender when pierced with a fork.
Drain the potatoes thoroughly and allow them to steam-dry for 2 minutes. Push through a potato ricer back into the warm pan. Beat in the 50g butter, 50ml warmed milk, and egg yolks until entirely smooth. Season generously with salt and white pepper, then transfer the mash into a piping bag fitted with a large star nozzle. Set aside.
In a wide saucepan, pour in the 600ml of milk. Gently add the cod, smoked haddock, and salmon pieces. Bring to a very gentle simmer and poach for 4 to 5 minutes.
Using a slotted spoon, carefully remove the partially cooked fish to a plate. Strain the poaching milk into a heatproof jug to reserve for the sauce. Once the fish is cool enough to handle, gently separate it into large, bite-sized flakes.
Wipe the large saucepan clean and melt the remaining 50g of butter over medium heat. Add the sliced leeks and saute for about 5 minutes until soft and translucent.
Stir the plain flour into the soft leeks and cook for 1 to 2 minutes to create a roux, stirring constantly to cook out the raw flour taste.
Gradually whisk the reserved warm poaching milk into the roux, adding a splash at a time to maintain a smooth texture. Bring to a gentle bubble and simmer for 5 minutes until the sauce heavily coats the back of a spoon.
Remove the pan from the heat. Gently fold in the flaked fish, raw king prawns, frozen peas, fresh dill, Dijon mustard, lemon zest, and lemon juice. Taste the sauce carefully and adjust seasoning if necessary. Pour the mixture evenly into a 2-liter baking dish.
Let the filling rest in the dish for 10 minutes to cool slightly. Starting from the outside edges and working inward, pipe the mashed potato over the seafood filling in decorative peaks. Preheat the oven to 200°C (400°F).
Bake in the preheated oven at 200°C (400°F) for 25 to 30 minutes, or until the sauce is bubbling up around the edges and the piped potato peaks are deeply golden. The internal temperature must reach 74°C (165°F) to ensure the raw prawns are thoroughly cooked. Let rest for 10 minutes before serving.
Chef's Notes
- Using a potato ricer guarantees a perfectly smooth mash that will glide through your piping nozzle without bursting the bag.
- Allowing the filling to cool briefly before piping the potato ensures the mash sits beautifully on the surface rather than sinking into a hot liquid.
- Smoked haddock is essential for the traditional depth of flavor; ensure it is undyed for the best quality and appearance.
- The egg yolks in the mashed potato are the secret to achieving distinct, sharp ridges that hold their shape perfectly in the oven's heat.
Storage
Refrigerator: 3 days — Store in an airtight container once completely cooled.
Freezer: 2 months — Freeze before baking for best results, or freeze leftover portions tightly wrapped.
Reheating: Reheat in a 180C oven until piping hot throughout, about 20-25 minutes. Microwave reheating is possible but will soften the potato crust.
