If you prefer, remove the bones and skin of the chicken breasts, pound them slightly between sheets of plastic wrap. Or leave the bones in and the skin on for baking or frying.
Season the chicken with salt and pepper.
Combine the ground walnuts, garlic, lemon zest, cayenne, and cinnamon with a little salt.
If sauteing the chicken breasts, heat the oil in a large saute pan over high heat and brown the breasts quickly on all sides. Set aside. Add the butter to the pan, saute the onion for 8 to 10 minutes over moderate heat until softened. Add the flour, stir well, and cook for about 4 minutes to get rid of the raw flour taste. Add the stock, stir well, and bring up to a boil.
Reduce the heat, simmer for a few minutes. Stir in the walnut mixture and adjust the seasoning with the lemon juice, salt, and pepper. Add 2 tablespoons of the dill or fresh coriander. Return the chicken to the pan to coat with the sauce and finish cooking.
Please taste again for salt, lemon, and herbiness. Sprinkle with the remaining herbs if you need their accent, and serve at once.