Mix all the sauce ingredients together and put to one side it is best to keep this chilled.

Place the haddock and bay leaves and parsley sprigs into a pan, pour over the milk cover, bring up to a boil, then lower the heat and simmer for 3 to 4 minutes. Now add the prawns, and take the haddock and prawns off the heat and let stand, covered, for about 10 minutes to finish cooking, the prawns will steam nicely and cook and become tender.

Put the potatoes into a pan cover with water and season with sea salt, bring to a boil lower the heat, and simmer for 10 to 15 minutes or until tender.

Now take the haddock and prawns from the milk with a slotted spoon and set aside to cool.

Drain the potatoes in a colander and leave for a few minutes to cool and drain a little, now put them through a potato ricer or mouli or just mash them by hand, we just want a light fluffy mash. Mix into the potatoes about 1 tablespoon of the sauce, lemon zest and parsley, season well with salt and pepper the potato should have a nice zesty flavour, so taste and fine-tune the seasoning.

Drain off any liquid from the haddock, grind some pepper over it, then flake it into the pan of potatoes slice the prawns into a similar thickness and then with your hands, gently lift the haddock and prawns and potatoes together so they just mix together it should only take a couple of turns, be careful you don?t want to allow the fish to break up too much.

Put the beaten egg into a shallow dish and lightly flour a board, spread the breadcrumbs on a baking sheet.

Divide the fish cake mixture into four cakes or 8 small cakes and on the floured work surface, and with floured hands, carefully shape the fish cakes about 1 inch thick. Then one at a time, coat each cake in the beaten egg, making sure the top and sides are coated, I like to use a pastry brush for this.

Now cover each cake one at a time in the breadcrumbs so that they are lightly covered.

Let chill for 30 minutes or so, you can make them ahead of time if you want.

Heat the oil in a large frying pan and fry the fish cakes over a medium heat for about 5 minutes on each side or until crisp and golden.

Serve with the tartare sauce and garnished with the watercress, spinach and rocket leaves and lemon wedges.

Enjoy!