Cold Noodles with Sesame Sauce

A perfect start to a Chinese meal, this can be prepared almost entirely in advance, varied in a number of ways, and even served as a main course if you like. Though it can be made with peanut butter (the natural kind, please, with no added sugar or fat), it’s easy enough to buy sesame paste (tahini) at health food stores, stores specializing in Middle Eastern or Asian ingredients, and even supermarkets.

Sesame oil, which contributes mightily to the flavor of the finished dish, is a