Chicken Peanut and Potato Stew

Heat the oil in a large, heavy frying pan over medium-heat heat; cook the chicken in the frying pan until completely brown, 5 to 7 minutes; remove and set aside. Add the onion, potatoes, garlic, pepper, salt, coriander, cumin and crushed chillies to the frying pan and cook until the onions soften, about 5 minutes. Stir in the water, chicken stock and peanut butter. Return the chicken to the frying pan and top with the spinach. Cover and simmer until the potatoes are cooked through, about 20 minutes.