Creamy Fish Pie with Fluffy Mashed Potato Topping

Preheat the oven to 220 degrees C. Bring two pans of water to boil. Salt one pan for the potatoes and add fish stock to the unsalted pan.

Peel and chop the potatoes. Add them to the salted boiling water and cook for 10-12 minutes until tender.

Meanwhile, separate the dill leaves into two halves. Finely chop one half for the fish mixture and set the other half aside for garnishing. Thinly slice the leek, baby fennel, and garlic. Cut the white fish fillets and salmon into 2 cm pieces.

In a large saucepan over medium heat, add oil. Once hot, add leek and fennel, cooking until softened. Add garlic and cook until fragrant.

Stir in the flour and wholegrain mustard, then gradually add in the stock while stirring constantly. Continue cooking until the mixture thickens.

Remove from heat and add in salmon, prawns, white fish, chopped dill, lemon rind, and some of the milk. Season with salt and pepper to taste.

Once potatoes are done, drain and return them to the pan over low heat. Add the remaining milk and butter, then mash until smooth. Season with salt and pepper.

Pour the fish mixture into an ovenproof dish, top with the mashed potato, sprinkle with grated cheese, and bake for 15-20 minutes until the potato is golden. Finish with a sprinkle of the remaining dill leaves and serve.