When it opened in 2015, the clean brick-walled space, gentle prices, and speedy counter service made this Shanghainese street-food destination feel like a chain in waiting. The big surprise might be that everything else on the menu delivers, too: Firm cold noodles stand up to their peanut dressing; chunks of chilled cucumber are tossed with garlic; and the pan-fried baos, with their pillowy tops and toasty bottoms, are among the best dumplings in New York.