Preserved mustard greens add an admirable umami note to noodles. But you might find your bowl also served with something fresh and crunchy such as baby bok choy or bean sprouts, or something savory like a hard-boiled egg.
The wheat noodles are not too thick and not too thin, explains Bob Liu, owner of Bob's Shanghai 66 in Rockville, and are cooked just until they're mostly tender but retain a satisfying chew.
Minced beef or pork is common, but some restaurants, such as Great Wall Szechuan House in Washington, opt for chicken. (Diners often can request that no meat be added at all.)
It packs an oily punch with dried red chiles, but is balanced with sesame paste and soy sauce. The addictive, lip-numbing zing comes from the piquant, floral Sichuan pepper, a member of the citrus family.
You can find dan dan noodles in a number of restaurants in the area (not to mention the country). Our favorites are in Rockville at Bob's Shanghai 66 (305 N. Washington St., 301-251-6652); in Annandale at A&J Restaurant (4316 Markham St., 703-813-8181); and in the District at Great Wall Szechuan House (1527 14th St. NW, 202-797-8888) and Panda Gourmet (2700 New York Ave. NE, 202-534-1620).
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