Xi An Gourmet, on Geary at Second Avenue, is a real find, an un-Americanized restaurant specializing in Sha'anxi food, the garlicky and noodle-heavy cuisine from a rugged province of Western China. While Yelp is only to be trusted as far as it can be thrown, the positive comments are united in one thing: what Xi An offers is a relative rarity, sitting among all the Cantonese restaurants in the Richmond, and San Francisco more generally. There's also House of Xian Dumpling in North Beach/Chinatown, but apart from the salt-and-pepper fried chicken, it's considerably inferior to Xi An.
Although there are formal menus, it's best to pour your dining companions tea and order off the walls, where dishes ranging from $4 to $20 are posted on individual, neon-colored sheets of paper. The mapo tofu with fish, silky and steamed just right, puts the pleasantly numbing burn of Szechuan peppercorns front and center. The Shanxi sandwich (with cumin lamb) wasn't a universal hit as the bread, like a stiff variant of a pita, wasn't too all tastes, but the heavily spiced lamb was undeniably delicious. (Xi An as a rule goes light on the subtlety).
Sha'anxi food leans more towards noodles than rice, and Xi An's hand-rolled version gives much to recommend. Both the sautéed noodles and the Shanxi noodles, the latter fairly drowning in chili oil, exhibited a perfect texture that avoided clumping even as leftovers the following day. As with many neighborhood Chinese restaurants, there's nothing of note in the decor, but for all its lack of nuance, Xi An fills a niche most perfectly.
Xi An Gourmet, 3741 Geary Blvd., (415) 668-5888.