Slice the onions, the potatoes and the tomatoes and place each one of them in a separate dish.
Heat the oil in a large pot. Arrange some of the onions at the bottom of the pot in one layer. Arrange a layer of the potatoes on top of the onion. Try to use as much of the potatoes as you can.
Place the Omani limes in a small Ziploc bag. Close the bag and smash the limes until coarsely smashed. Sprinkle half the amount on the potatoes in the pot.
Sprinkle the potatoes with 1 tsp turmeric, some salt and some black pepper.
Place the chicken thighs in a large bowl. Sprinkle 2 tsp turmeric, salt and pepper and rub it in well.
Arrange the thighs as the next layer in the pot.
Top with the rest of the onions, the sliced tomatoes and the rest of Omani lime.
Cover the pot, lower the heat to medium low and cook for 45 minutes. Then turn the chicken upside down, cover the pot and cook for 45 more minutes.
Serve with some good bread to dip in the sauce and enjoy.
