Ahuna meat is one of the best mutton recipes and this is a very oldest traditional way of Indian cooking. This must be considered as an iconic dish of India. Instead of Shahi, korma etc.
Sardar Ji, may be it's a good replica of Champaran mutton, but the real Champaran mutton is still runs in Patna (Kankarbagh, area). N moreover they also provide a cozy environment to seat and eat with family.