‘Tahcheen’ means ‘spread over the bottom’ and the whole point of this dish is to end up with a lot of lovely golden crunch under the rice. Obviously, the wider and shallower the baking dish, the greater the crunch-to-rice ratio will be. On the other hand, if you bake the rice in a deeper, attractively curved or domed dish, it will look like a gorgeous golden cake when turned out, the secret filling revealed on cutting. The most important thing is that it be heavy duty to ensure even cooking all over – a Pyrex or heavy ovenproof porcelain dish would be ideal.
Tahcheen is a brilliant dish for entertaining, as once the preparation is done it just bakes away by itself for a couple of hours
In this recipe the lamb needs to be slow-cooked first, and then marinated for a minimum of 8 hours for the flavours to develop. Omit the prunes, if you like, but somehow I think they contribute to the essential ‘Persian-ness’ of the dish.