This classic Persian dish was originally made with game birds, but is fine with chicken - or duck if you prefer. With its scattering of pomegranate seeds and walnuts it is very decorative. Disjoint a chicken (or use chicken pieces) and brown in a little olive oil in a heavy pan with a lid. Remove the chicken and set aside. Brown chopped onion in the remaining oil. Add walnuts and cook gently for a minute or so. Add juice of pomegranates and lemon, brown sugar, cinnamon, and salt and pepper to taste. Bring to a simmer and return the chicken to the pan. Cook gently for 1 1/2 hours until very tender. Taste and adjust the sweet-sour balance if necessary. Serve over steamed rice and scatter over the dish the seed sacs of the remaining half pomegranate and a handful of coarsely chopped walnuts.