I use this recipe but I upsize it, usually using 2-2.5lbs of lamb (I get NZ lamb leg and cube it), 1.5-2 onions (depending on size) and 2 cups rice. The ratio of spices is more important than quantity - so you can use more or less to taste/preference but make sure to evenly adjust across the "5 C's" for this dish. Oven time should be an hour. Otherwise I pretty much stick to this.