This scrumptious fish pie will be a firm family favourite!
Preheat the oven to 180°C/fan 160°C/gas mark 4. Grease a pie dish with butter.
Boil the potatoes until soft, then drain, mash and set aside.
While the potatoes are cooking, heat the oil in a non-stick frying pan and fry the onion and leek for a few minutes until soft. Set aside.
Melt the butter in a saucepan. Add the flour and cook for a couple of minutes, stirring frequently. Gradually add the milk over a low heat, whisking or stirring continuously until the sauce starts to thicken. Season.
Add the fish, onion and leek mixture, frozen peas and parsley into the sauce and gently mix together. Transfer to the prepared dish then top with the mashed potato and sprinkle over the cheese.
Bake for 40 minutes or until golden on top. Serve with seasonal veg.