Known simply as Lǐjì (pronounced 'lee jee'), this popular place has two outlets close to each other on Ya'er Hutong, both of which serve great-value Chinese Muslim dishes and snacks.
The first one you come to, if walking from Silver Ingot Bridge, is the main sit-down restaurant (look for the long, green-and-yellow sign). It has an English menu, including grilled skewers, lamb dishes and noodles, and is basic but clean. Further on is a smaller, older branch, which specialises in boiled tripe (爆肚; bàodǔ) and has an adjacent takeaway-dumplings stall, which is very popular at breakfast time: try the beef and onion dumplings (牛肉大葱包子; niúròu dàcōng bāozi; ¥2 each). It also roasts very good sesame-seed buns (烧饼; shāobing; ¥1 each), which you can have filled with lamb (烧饼夹肉; shāobing jiā ròu; ¥7 each).