1 Scrub the potatoes clean. I never peel them as there's so much goodness in the skin, but do as you prefer. Parboil them till almost cooked but still a little firm. You need to be able to slice them thickly so they need to remain a little undercooked. Drain and set aside.

2 Rub a teaspoon of butter around the inside of an ovenproof dish. Cut the haddock into cubes and place in the base of the dish, scatter with parsley and the finely sliced spring onion. Season with salt and pepper.

3 Heat the milk, cream and Dijon mustard in a pan till warm, and whisk to combine. Pour half this mixture over the fish.

4 Once the potatoes are cool enough to handle, slice them thickly. Arrange the potato slices over the fish and pour the remaining cream mix over the top. Season with a little salt.

5 Scatter the cheese on top and bake in a hot oven, 220 degrees, for 20 minutes till golden, bubbling and cooked through. Serve with salad or greens such as broccoli or spinach.