Toss the chicken thighs in half the spices and a pinch of salt until completely coated. Heat 1 tbsp oil in a large sauté pan with a lid. Fry chicken, skin-side down, for 10 mins until golden brown, turn over, then cook for 2 mins before removing from the pan. Pour the rest of the oil into the pan, then fry the onions and garlic for 8 mins until golden. Stir in the rest of the spices, then cook for 1 min longer. Pour over the chicken stock and scatter in the olives. Bring everything to the boil, turn down the heat, then sit the chicken, skinside up, in the stock.