Prepare the burgers: Finely chop half of the coriander leaves, discarding the stems. Put the lamb mince, the dried spices and the chopped coriander in a mixing bowl. Crush the cloves of garlic into the bowl. Season generously with salt and pepper. Mix all the ingredients together well with your hands, squishing and turning it. Making sure you’ve broken down the mince so that it clings together in a ball. Divide into six equally sized balls and press them flat into burger patties. During cooking the patties will draw in, becoming fatter and less spread-out, so make them wider and thinner than you would like them. Separate the burger patties with grease proof paper and put them in the fridge while you make the raita. Burgers may be made a couple of days before they're needed. Keep covered in the fridge to prevent drying out.