Put the coriander stalks in your food processor (reserving the leaves), then drain the mixed beans and add, along with the broad beans, a pinch of salt & pepper, the cayenne, cumin, coriander, grated lemon zest and flour.
Whiz until fine & combined, scraping down the sides of the processor if needed.
Tip the mixture onto a generously flour-dusted board, divide into 4 pieces, then roll each piece into a ball and flatten into a patty about 2.5cm thick, dusting your hands and the burgers with flour as you go.
Pour 1 tablespoon of olive or rapeseed oil into the frying pan, followed by the burgers, pressing them down with a fish slice & flipping them when golden.
Swap to grater in the processor, then grate the cabbage and peeled onion and tip into a bowl.
Chop the coriander leaves and add, with the yoghurt, mustard and the juice of the zested lemon, then toss and season to taste.