To make the spice blend: Stir the top four ingredients together in a small bowl and set aside.
To make the sauce: Melt the butter in a 12-inch nonstick skillet over medium heat. Add the onion and cook, stirring frequently, until the pieces just begin to turn gold, about 5 minutes. Add the garlic, tomato paste and spice blend, and cook for 1 minute, stirring constantly to prevent burning. The spices will be fragrant. Add the tomato sauce and stir will. Add the chicken pieces, spoon the sauce over the top and bring to a simmer. Turn the heat to low and cook, uncovered, until the chicken is warmed through and the sauce is flavorful, about 10 minutes. Stir frequently. Shake any excess water from the peas. Add the peas and cream to the sauce in the pan, stir well and heat through. Do not boil. Serve over Bastami rice and garnish with chopped cilantro.