Sprinkle ¼ teaspoon of ground saffron over 3 ice cubes in a small bowl and let them melt at room temperature. Cook 1 cup of green lentils in boiling water for 20 minutes, then drain and rinse with cold water.
Boil 2½ cups of basmati rice in a large pot of salted water for 5-7 minutes, until tender outside but still firm inside. Drain and mix with the lentils.
Pour 4 tablespoons of neutral oil into the pot and cover the bottom with 1 sliced russet potato. Mix 1 cup of the rice and lentils with the saffron water.
Layer the remaining rice and lentils over the potato, mixing in the saffron rice. Poke a few holes in the top and dot with half of 6 tablespoons of butter. Cover and cook over medium heat for 45 minutes.
Meanwhile, heat 2 tablespoons of olive oil in a pan and cook 1 chopped onion until soft. Add 450g of ground beef, breaking it up.
Stir in ½ teaspoon of turmeric, ½ teaspoon of cinnamon, 1 teaspoon of kosher salt, and ¼ teaspoon of black pepper, and cook until the beef is browned and cooked through.
In a small pan, sauté 1 cup of raisins and 1 cup of pitted dates in the remaining butter until warmed through.
Let the rice rest off the heat for 10 minutes. Serve it topped with the beef, raisins, and dates, with the potato tahdig alongside.
