Add the stock to the pan with the haddock and pollack. Bring to a simmer
Simmer for five minutes then let the fish sit for five minutes
Flake the fish into chunks and place in a large ovenproof dish
Keep the stock
Add the prawns, chopped dill and peas to the dish
Add the wine, cream and left over stock to a pan
Bring to a simmer
Mix the cornflour with some water to form a paste
Whisk into the sauce stirring all the time until it thickens
Add the sauce to the dish with the fish
Boil the potatoes for 15 minutes until soft
Drain and return to the pan
Mash the potatoes
Chop the spring onions and chives and mix into the potatoes
Add to the top of the dish
Grate the cheese and sprinkle over the top
Preheat oven to 220C/200C fan/gas 7.
Cook for 20 -25 minutes until golden