Saute onion, salt, and pepper in red palm oil for 10 minutes.
Add chicken and turmeric. Cook until browned, adding water as needed to keep the chicken from sticking to the pan. I recommend adding the 2 cups of water as needed (i.e. the water level is getting low).
Add turmeric and saffron. Bring mixture to a boil. Add tomato paste and let simmer for 45 minutes.
Right before serving, add potatoes and cook until soft and tender (approximately another 25 minutes). Serve with rice.
For the yogurt sauce, blend yogurt, cilantro, and lime juice in a high speed blender. Serve alongside chicken and rice.