Wash the chicken, dab dry and cut into pieces. Mix 150 grams of yoghurt, sugar and spice mixture and coat the chicken parts with it. Marinate the chicken parts in a cool place for about 1 1/2 hours.
In the meantime, peel and wash the potatoes and cut them in half lengthwise. Clean, wash and cut the spring onions into pieces. Clean, wash and halve the mushrooms. Put chicken pieces on a greased baking tray and bake in the preheated oven (electric cooker: 200°C/ gas: level 3) for 45 minutes.
Heat the oil in a pot, fry the potatoes and mushrooms, add the stock and cook for 20 minutes. Add peas and spring onions after twelve minutes of cooking time and cook with them. Wash the coriander, dab dry and pluck the leaves from the stalk.
Season the remaining yoghurt with salt, pepper, sugar and curry. Arrange chicken pieces and yoghurt dip on a plate and serve sprinkled with coriander. Add vegetables garnished with coriander and sprinkled with pepper.