Peel and quarter the potatos and bring to boil in a pan of lightly salted water for around 20 mins

Add the milk stirring constantly to avoid the white sauce going lumpy, and bring to the boil to thicken. Add the peas to the sauce, season with onion powder, salt, pepper and a bay leaf and take off the heat

Drain the potatos, add around 50g butter, a good splash of milk around 150mls, season with salt and pepper then mash them. They need to be wet enough to pipe or spread. Add more butter etc according to own taste

Cut the fish into inch chunks and alternate in a single layer on the bottom of an ovenproof dish

Pour the peas and sauce over the fish, remember to remove the bay leaf

Spread the mashed potato on top, sometimes I add a sprinkle of nutritional yeast for a cheesy flavour but of course you could just use grated cheese

Bake at gas 8 / 220C for 25-30 minutes until the potato starts to crisp and the sauce starts to seep through the mash