Preheat the oven to 180°C/Gas 4.

Boil the eggs for 8 minutes and set aside.

Boil the potatoes for 15-20 minutes or until tender then mash.

Place the milk in a large saucepan and bring to the boil and reduce to a simmer. Add the fish skin side up and gently cook for 5-7 minutes.

Take the pan off the heat and gently lift out the fish onto a plate. Take off the skin and flake the fish into large chunks discarding any bones.

Strain the milk through a sieve and put it back in the saucepan to heat up again.

Mix the cornflour with a little water and add to the hot milk and stir until thickened. Mix in the mustard.

Add the fish back in along with the quartered eggs and dill. Add the zest and half the lemon juice. Fold gently and taste to see if you need to add the rest of the lemon juice before spooning into a casserole dish and topping with the mash.

Bake in the oven for 20-25 minutes until golden and bubbling.

Serve immediately with extra veg of your choice or my lemony greens