Step 1

Heat grill to high. Tip the beans into a large bowl, then roughly crush with a potato masher. Add the breadcrumbs, chilli powder, coriander stalks and ½ the leaves, egg and 2 tbsp salsa, season to taste, then mix together well with a fork.

Step 2

Divide the mixture into 6, then wet your hands and shape into burgers. The burgers can now be frozen. Place on a non-stick baking tray, then grill for 4-5 mins on each side until golden and crisp. To cook from frozen, bake at 200C/fan 180C/gas 6 for 20-30 mins until hot through.

Step 3

While the burgers are cooking, mix the remaining coriander leaves with the yogurt, lime juice and a good grind of black pepper. Split the buns in half and spread the bases with some of the yogurt. Top each with leaves, avocado, onion, a burger, another dollop of the lime yogurt and some salsa, then serve.