In a heavy pot over medium heat, combine 900ml reserved stock, soaked rice, leftover ghee mixture from sautéing, salt to taste and half of the spice mixture that's left (¼ of total amount made). Stir to combine.
Add the lamb shanks on top and cook covered until most liquid evaporates.
Check on the rice after about 10 minutes and move things around a bit to distribute the stock to the bottom of the pot.
Layer sautéed carrots and sultanas on top of the rice - do not stir to combine yet.
Cover the pot with a clean kitchen cloth and top that with a lid. Steam on low heat for around 20–25 minutes until rice is fluffy.
Serve hot. Leftovers reheat well and can be kept in the fridge for 2-3 days.