Had this every second day in Tehran. Delicious, either made on a grill or with a cast iron grill pan.
for the marinade:
1 onion, thinly sliced
250 grs full fat yoghurt (10% Greek/Turkish style)
juice of one lime or lemon
2 tsp olive oil
1 gr. saffron (1/2 tsp)
2 tsp salt
pepper
1 kg chicken breast, cut into cubes, about 2 cms
5 tomatoes, halved, or 10 cocktail tomatoes
baste (optional):
juice of 1 lime or lemon
50 gr. butter
1/2 tsp salt
pepper
Grind saffron and salt with a pestil and mortar. Dissolve with 2 tbsp hot water. Add remaining ingredients and mix well. Add the chicken, mix, cover and marinate for at least 6 hrs to 2 days.
Thread on skewers with tomatoes and slowly grill on a charcoal grill or a grill pan. Optionally paint with the baste during the grilling and just before serving.
Serve with a cucumber yogurt and flat bread or with basmati rice topped with a knob of butter and a raw egg yolk.
source: New Food of Life - Najmieh Batmanglij