Cut the potatoes in half. Add them to a large saucepan, cover with cold, salted water and bring to a simmer over medium heat. Cook for 10 minutes, or until firm. Drain and leave to steam dry.
Finely slice the shallot, cut the leek into rings, and finely chop the fresh dill.
Use a large baking tray (the size of the puff pastry). Add some olive oil to the tray. Place the cooked potatoes, mixed seafood, shallot, dill leaves and leeks in the olive oil in the shape of the puff pastry. Drizzle the cream over the ingredients. Season with salt, pepper, and fish seasoning.
Place the puff pastry on top of the fish and vegetables and, using a fork, press the ends down.
Beat the egg in a small bowl. Brush the surface of the pastry with the egg and place in the oven for 30-35 minutes until golden brown.
Remove from the oven and turn up-side down. Serve with the mixed salad leaves.
