Boil a large pot of salted water. Add the rice and millet, cook for 5 minutes, then drain.
Build the tahdig crust: In a heavy-bottomed pot, heat 2 tbsp olive oil. Stir in yogurt, turmeric, cinnamon, allspice, cumin, cardamom, and a pinch of salt and pepper until a paste forms. Spread evenly across the bottom.
Layer the rice: Add one-third of the rice, pressing it flat. Add a second layer, then scatter over the almonds, cranberries, raisins, carrot, and orange peel. Finish with the remaining rice, pressing down gently.
Steam: Wrap the pot lid with a clean kitchen towel, cover tightly, and cook over very low heat for about 70 minutes, until the rice is fluffy and a golden crust has formed.
Serve: Invert onto a large serving platter. Garnish with extra almonds, cranberries, carrot, and orange peel. Serve warm.