Coat the chicken thighs in the paprika, ground allspice, turmeric and salt and leave for 10 mins. In the meantime chop the vegetables.
Spray a large pan with some low calorie cooking spray and heat gently.
Cook the chicken thighs until they start to brown. Turn them over and brown the other sides.
Set the chicken aside.
Add a few more sprays of low calorie cooking spray to the pan, then fry off the onion, carrot, celery, garlic and mushrooms until the onion is soft.
Add the tomatoes, lemon juice and 100ml of the chicken stock. Return the chicken back to the pan and place in the oven with a lid on (or covered with foil) for 30 mins at 180°C.
Carefully remove the pan from the oven, add the orzo, parsley and the rest of the stock, stir, and return to the oven for 20 mins with the lid off