Toast chopped walnuts in a large frying pan over medium heat (stir and watch to avoid charring): transfer to a bowl and set aside.
Melt butter in a large frying pan over medium heat: add onion and chicken; stir and cook until the chicken pieces are no longer appear pink.
Add garlic, cinnamon, red pepper and salt; cook two minutes more.
Blend in tomato paste. Add walnuts and pomegranate juice and bring just to a boil. Reduce heat, cover and simmer 15 to 20 minutes.
Serve over rice. (Garnish with pomegranate seeds if fresh pomegranates are used.)