What goes into a proper tahdig

The crust at the bottom of the pot. Everybody fights over it and almost nobody makes it right at home.

Tahdig is the crisp layer at the bottom of the rice pot, and it is the first thing to disappear from any table.

Three things matter. The rice must be par-boiled and drained properly, so it steams rather than boils. The base needs fat and a little yoghurt or saffron water, poured before the rice goes back in. And the heat must be low for a long time — forty minutes at least, and you do not lift the lid.

If you can hear it crackling you are close. If you can smell it you are already late.