The humble Ploughman's Lunch is a thing of beauty. Reliable, comforting, nostalgic. These Ploughman’s croquettes take a little more effort, but with their golden crust, gooey centre, and tangy hit of pickle, the payoff is more than worth it.
Peel and cube the potatoes, then boil in salted water until tender. Drain well and let them steam dry for a couple of minutes, then mash with the butter until smooth but still on the dry side.
Grate 150g of the cheddar and cut the remaining 100g into small cubes. Stir the grated cheddar into the warm potato so it melts slightly, then mix in the ham hock, pickled onions, cornichons, mustard, a little salt, and plenty of black pepper.
Spread the potato mixture onto a shallow tray and chill until cool enough to handle. Divide into 10 equal portions. Take one portion, flatten it in the palm of your hand, place a cube of cheddar and half a teaspoon of pickle in the centre, then fold the potato around the filling to seal. Roll into a neat cylinder. Repeat with the remaining portions, then chill the croquettes on a tray in the fridge for at least 30 minutes.
Roll each croquette in flour, dip in beaten egg, and coat in breadcrumbs. For extra crunch, repeat the egg and breadcrumb step.
Heat the oil to 170–180°C and fry the croquettes in batches for 3–5 minutes, until golden and crisp. Drain on kitchen paper or a wire rack, and serve hot with slices of tart green apple and a mustard mayonnaise for dipping.