There is a home in Beijing, at the intersection of North Third Ring Road, Jimen Bridge East and Xingtan Road. If you leave from Beijing Railway Station, take Metro Line 2, change to No.22 at Qianmen, and arrive at Beitaipingqiao West.

Although I showed you the way, I still advise you, brother, it is not the best for me to soak mutton in Xi 'an. You can see if there are any locals in Xi 'an eating at Lao Sun's house. Ask the local people in Xi 'an, and you will know that Lao Sun's family sells a brand. The mutton bubble is too common, and it is for foreigners.