Four hours, or at least two hours before you would like to cook the chicken, marinate the thighs firstly in the juice and zest of 1/2 a lemon and a sprinkling of salt, leave for 15 minutes. Now blitz 5 tablespoons of the yogurt, spices , onion and garlic.
Preheat the oven 180C/Gas 4. Put the chicken and marinade in a single layer on a baking tray or oven proof dish. Slice the remaining lemon and combine with the chicken. Season with salt and pepper. Place in the oven for 30-40 minutes or until cooked through.
While the chicken is cooking make the slaw. Shred the cabbage and kale finely and slice the red onion finely too. Chop the chilli finely. Combine all the vegetables in a bowl and sprinkle over the salt, toss and leave to stand for 10-15 minutes. Mix together the oil and vinegar and add to the slaw, finely chop the mint and add to the salad.