Heat the olive oil in a saucepan and gently fry the celery, carrot, onion, garlic, rosemary and bay leaves until golden, about 15 minutes.
Remove the rosemary sprig and bay leaves and season with salt and freshly ground black pepper. Add the grated lemon zest. Set to one side.
Meanwhile, for the chicken, mix the flour with the salt and freshly ground black pepper and coat the chicken pieces in this mixture.
Heat the olive oil in a frying pan and fry the chicken until golden brown. Add the wine and cook for five minutes.
Add the chicken and wine reduction to the soffritto, then add half the lemon juice and cinnamon. Stir well.
Add the stock and cook on a low heat for about 45 minutes, or until the sauce has reduced and the chicken is completely cooked through. Keep the pan covered for the first 30 minutes of cooking.
Remove the cinnamon sticks, then mix the egg yolk with the remaining lemon juice. Quickly but carefully stir this mixture into the sauce until blended. Serve immediately.