Rinse the rice several times until the water runs clear, then parboil it in salted water until the grains are just tender; drain well.

Warm the butter or oil in a heavy pot and swirl in a little of the saffron water to tint the base a golden colour.

If you prefer a potato or bread tahdig, arrange the potato slices or lavash in a single layer at the bottom of the pot before adding the rice.

Spoon the rice into the pot gently, shaping it into a mound and drizzling the remaining saffron water on top for aroma and colour.

Cover the pot and cook over medium heat for a few minutes, then reduce to low and steam for twenty-five to thirty minutes until the tahdig forms and the rice becomes fluffy.

Let the pot rest briefly, then invert it onto a platter so the tahdig releases in one golden, crisp disc.

Serve immediately, breaking the crust into shards for everyone to share.