neutral-flavored oil • thin flour "yangchun noodles", Chinese egg noodles, or other thin egg noodle • Chinese sesame paste • furu (fermented tofu), from 13-ounce jar • toasted sesame oil • light soy sauce • sugar • Chinese black vinegar • dark soy sauce • Sichuan peppercorn oil • salt • mayonnaise, preferably Kewpie •