Place the peeled and chopped potatoes in a large pot of salted water, bring to a boil, and cook for 15-20 minutes until tender.

While the potatoes are boiling, place the smoked haddock in a large saucepan and cover with the milk.

Bring the milk to a gentle simmer and poach the fish for about 5 minutes until it starts to flake, then remove the fish with a slotted spoon and reserve the milk.

In a separate saucepan, melt 50g of butter over medium heat and stir in the flour, cooking for 1 minute to make a roux.

Gradually whisk in the warm reserved poaching milk until you have a smooth, thick white sauce, then stir in half of the grated cheese and the parsley.

Drain the cooked potatoes and mash them thoroughly with a knob of butter and a splash of milk until smooth and creamy.

Preheat your oven to 200°C (400°F).

Flake the cooked haddock into a large baking dish, discarding any skin or bones, and scatter the raw prawns and frozen peas over the top.

Pour the creamy cheese sauce over the fish and vegetable mixture, stirring gently to combine.

Spoon the mashed potatoes over the filling, spreading it out with a fork to create a textured top, and sprinkle with the remaining cheese.

Bake in the preheated oven for 25-30 minutes until the top is golden brown and the filling is bubbling at the edges.

Let the pie rest for 5 minutes before serving hot with a side of steamed green beans or broccoli.