Step 1

Mix all the sauce ingredients together. Set aside.

Step 2

Lay the fish and bay leaves in a frying pan. Pour over the milk and water. Cover, bring to a boil, then lower the heat and simmer for 4 minutes. Take off the heat and let stand, covered, for 10 minutes to gently finish cooking the fish. Lift the fish out of the milk with a slotted spoon and put on a plate to cool.

Step 3

Meanwhile, cook the potatoes in the salted water for 10 minutes or until tender, but not broken up. Drain the potatoes and leave them for a minute or two.

Step 4

Tip them back into the hot pan on the lowest heat and let them dry out for 1 minute, mashing them with a fork and stirring so they don't stick. You should have a light, dry fluffy mash. Take off the heat and beat in 1 tablespoon of the sauce, then the lemon zest, parsley, pepper and chives. Set aside.

Step 5

Drain off liquid from the fish, then flake it into big chunks into the pan of potatoes. Using your hands, gently lift the fish and potatoes together so they just mix. Do it with only a couple of turns, or the fish will break up too much. Put to aside and cool.

Step 6

Beat the egg on a large plate and lightly flour a board. Spread the breadcrumbs on another plate. On the floured board, and with floured hands, carefully shape into 4-6 cakes, about 2.5 cm thick. One by one, put each cake in the egg, and brush over the top and sides so it is completely coated. Transfer each cake to the plate with bread crumbs, pat the crumbs on the sides and tops so they are lightly covered. Transfer to a plate, cover and chill for 30 minutes (or up to a day ahead).

Step 7

Fry the fish cakes in hot oil over a medium heat for about 5 minutes on each side or until crisp and golden. Serve with the rest of the sauce (squeeze in a little lemon zest to taste) and lemon wedges for squeezing over.