Set out a scale and the equipment for Tahdig. Heat to a quiet simmer, about 195°F / 90°C and give it 5 minutes so the surface is actually hot. Weigh dry basmati rice, greek yogurt, 2%, saffron, egg, olive oil, unsalted butter, kosher salt. Tahdig is cooked in Tehran as its own plate, not as a copy of a restaurant menu. Parboil the rice, then cook it covered with a yogurt crust until the bottom turns gold. Amounts are for 4 from foods this library can count.