Preheat your oven to 180°C. Rinse the basmati rice several times until the water runs clear. In a large bowl, combine the plain yoghurt, eggs, saffron liquid, and a pinch of salt. Stir gently to create a smooth, vibrant mixture, ensuring the saffron is evenly dispersed before moving on to the next step.

Place the chicken pieces in a pan with the sliced onion, turmeric, cinnamon, salt, and pepper. Add enough water to cover, then simmer until tender. Remove the chicken, shred it into even strips, and taste for seasoning, adjusting as needed. Allow it to cool slightly before mixing further.

Bring a large pot of salted water to a boil. Add the rinsed rice and cook until the grains are soft on the outside but firm within. Drain thoroughly and rinse briefly with warm water to stop the cooking. This ensures long, separate grains once baked.

Fold two thirds of the parboiled rice into the saffron yoghurt mixture. Do this gradually to coat every grain without crushing the rice. Keep the remaining rice plain for layering in later steps.

Grease an ovenproof dish generously with butter or oil. Spoon half of the saffron rice mixture into the base and press it down firmly with the back of a spoon. Compacting this layer helps form the signature crisp crust known as tahdig.

Spread the shredded chicken evenly over the compact saffron rice. If using barberries, sauté them lightly with a little sugar and oil before scattering them over the chicken. This adds a tart lift to the dish.

Cover the chicken with the rest of the saffron rice mixture, followed by the remaining plain rice. Smooth the surface and press gently. A tight structure ensures even browning and a neat shape once unmoulded.

Cover the dish with foil and bake for 45 minutes. Remove the foil for the final 15 minutes to deepen the colour and crispness. Listen for a gentle sizzle at the edges which signals that the crust is forming properly.

Let the Tahchin rest for 10 minutes. This allows steam to settle and helps the rice cake lift cleanly from the dish. Loosen edges with a thin spatula before unmoulding onto a serving plate.

Slice the Tahchin carefully and serve with extra barberries, yoghurt, or a simple herb salad. Highlight the golden crust when plating, as its colour and texture are the pride of a well-made Tahchin.