Heat the butter or oil in a suitable casserole and sauté the onion cubes until translucent. Take out and sear the meat well over high heat (maybe add a little more oil or butter). Sprinkle with cinnamon, stir in and pour in water. Season with salt and pepper and stew covered for approx. 1 1/2 hours.
Fry the rhubarb in butter in a pan for a few minutes. Add lemon juice to the rhubarb (not too much, otherwise it will get really sour!). Simmer for 3 minutes, then add to the meat. Let simmer for another 10 minutes.
Rice, couscous or my favorite, mashed potatoes with dandelion (just mix the dandelion into the hot puree) tastes good with it.
I`ve had this recipe for many years and I cook it every spring. But I`m not sure if the name is correct and if it is even Iranian.