Peel and chop the potatoes into even sized chunks. Put them into salted boiling water and simmer for about ten minutes until they are tender and a knife cuts through them easily.
Drain the potatoes and leave to steam dry.
Meanwhile, lay the cod fillets in a frying pan, pour in the milk, and then top it up with water until it's almost covering the fish. Add the thyme, bay leaves and garlic cloves.
Bring to the boil, then lower the heat and simmer for about 8 minutes to gently cook the fish. Leave to stand for ten minutes, then transfer the fish onto a plate and discard the liquid.
For the sauce, add all the sauce ingredients into a mixing bowl and mix well until combined.
Once the potatoes are cooled slightly, use a whisk or a fork to mash the potatoes. You should have a light, dry and fluffy mash.
Beat in 2 tbsps of the sauce into the potatoes, then the zest and juice of the lemon, chopped parsley and chopped chives. Mix it well and season with salt and pepper.
Flake the fish into the bowl, then fold it through being careful not to break the fish up too much.
Mould the mix into fish cakes, if the mix is soft then chill it in the fridge for a while.
Coat the patties in the flour, then the eggs and finally the breadcrumbs.
Heat some oil in a large frying pan, cook the fish cakes until golden and crispy on both sides.
Serve with a dollop of the sauce, a lemon wedge and some salad leaves.
