Put the brine ingredients into a saucepan, bring to the boil then simmer for 5 minutes to bring out the flavours. If you don't want seeds in the finished relish, strain them out now.

Add the cauliflower, capsicum and beans to the brine and simmer for 5 minutes: you want them still very crunchy at the end. Drain the vegetables into a colander over a bowl, returning the brine to the pan and letting it cool slightly. Add the onions and cornichons to the vegie mix in the colander and leave both until the sauce is ready.

Whisk the chickpea flour and mustard seeds with a ladleful of the warm brine until smooth, then stir it back into the remaining brine with the sugar and bring to the boil. Check the flavour for sweet-sour balance and seasoning and adjust to taste. Add the drained vegetables, onions and cornichons, bring to the boil then bottle and seal while hot.

Tip: I don't salt the vegetables overnight, a step that would give more crispness, but you might do this. And I do the lazy-man thing of using ready-pickled cornichons and silverskin onions (the tiny sort you would serve in a Gibson cocktail), as they're hard to buy fresh and fiddly to prepare.

More of Dan Lepard's DIY Christmas hamper recipes here