Pour rice into a large bowl and fill with water. Rinse several times until the water runs clear, about 6-7 times and then soak the rice for 1 hour.
In a small pot, add lentils and 1 1/2 cups of water and bring to a boil. Once boiling, reduce to a simmer and cook lentils for about 10-15 minutes or until liquid has evaporated and lentils are tender. Season with salt and pepper and set aside.
In another pot, add rinsed rice and 4 cups of water. Boil rice until it is half way cooked and soft on the outside but firm on the inside, about 10 minutes. You don't want to cook the rice fully because it will continue to cook later. When done, drain and rinse the rise. Set aside.
In another small pot, drizzle olive oil and saute chopped onion until caramelized. Then add barberries (or dried cranberries if that's what you can find), salt, 1/2 tsp turmeric and 1/2 tsp cinnamon. Toss to combine and remove from heat and set aside.
Finally (last pan, promise), drizzle a large skillet with olive oil so it coats the bottom. Add 1/2 tsp turmeric and lay potatoes in an even layer.
Mix lentils and rice together and add that on top of potatoes.
Then add the barberry-onion mixture and figs and lay on top of rice.
Drizzle saffron water over the top of everything and poke holes with the back of a large wooden spoon. This will help the steam to escape and the bottom to get crispy.
Next, cover the lid with a clean towel and close lid on pan. Cook on high for about 10 minutes so the potato gets crispy then decrease heat to low for 20 minutes so the rice is fully cooked.
When done, remove lid and serve rice with potato tahdig on the side.