On a mackerel charter trip you can take home a bucket-full of fish, but it's better to keep what you would use in just a couple of days. The mackerel won't be suitable after a few days out of the water anyway, so there's no pointing wasting fish.
Pennywort leaves are common on coastal cliffs and stone banks, especially in the south-west and are easily foraged. They are one of my favourite edible weeds with a great texture, look and flavour.
300-350g mackerel fillet, boned
100-150g gluten-free self-raising flour
Vegetable or corn oil for deep frying
A few handfuls of pennywort leaves
3-4tbsp pickled walnut liquid
Salt and freshly ground black pepper
I've used the liquid from pickled walnuts here as usually it ends up going down the sink, which is a shame because the flavour is fantastic, like a fruity, aged balsamic vinegar.
Put the walnut liquor in a pan, bring to the boil and simmer until it's reduced by half, then transfer to a small dish to cool.
Preheat about 8cm of oil to 160-180C in a large thick-bottomed saucepan or deep-fat fryer. Cut the fish into chunks of about 2cm square. Season it, then pass through the flour, shaking off any excess.
Next pass it through the milk, and then again through the flour. Deep-fry for 2-4 minutes, turning the fish with a slotted spoon as it cooks, until crisp and golden. Remove from the oil and drain on kitchen paper.
Wash the pennywort and arrange on plates with the mackerel, season, and pour a teaspoon of the walnut liquor (and a little oil if you like) over and around the leaves.