In a large saucepan, fry the onions (and chicken if using raw chicken) until the onion starts to brown. Add the garlic & ginger and saute for another 2-3 minutes.
Add the spices and stir to combine.
Add the rice and stir to coat the rice in the spices.
Add the chicken stock and turn down the heat. Allow to simmer gently for 10-15 minutes until there is only a little bit of stock left in the pot and the rice is almost cooked.
Add the shredded chicken (if using cooked chicken) and turn the heat off and place a lid on the pot. Allow to steam for 15-20 minutes until the rice is cooked.
When the rice is cooked, fluff it with a fork and stir in the lemon zest, juice and pistachios.
Serve with fresh parsley.