Soak rice and whole red lentils separately for 1 hour
Soak saffron in 1/4th cup of water
Peel potatoes and slice them like round chips, not too thick nor very thin.
Cook rice in salted water till half done. Drain. Same way boil masoor (whole red lentils) until almost done but firm. Drain it too.
Keep everything ready to assemble
Take a non stick vessel put 3 tbsp oil and arrange potato pieces in such a way that it covers the base and sides of the pan
Mix boiled rice and masoor, add little salt and without disturbing the potato layer put this mix gently over the potatoes.
Pour remaining oil from sides and little on top of the rice lentils mix. Add half cup of water very gently. Keep the bowl of Saffron in water over the rice.
Cover with the lid, make sure that stem does not escape from the lid. On very slow flame cook for half n hour. Do not stir.
Open the lid and pour the Saffron water over the rice. Close and cook for another 5 min.
Switch off the flame and let it rest for 10-15 minutes.
Now take a tray or big plate. Open the lid and put the plate/tray on the vessel. Turn the vessel upside down. Tap a little so that entire rice along with potato layer comes out on tray in one piece like a cake.
This persian rice is usually served with some meat gravy, minced meat ball curry or vegitable raita.