This recipe is in the Pasta chapter (subchapter: Noodles), possibly as a reminder to the reader that there is a world of pasta beyond Italy. It could just as easily fit into the Vegetarian chapter, because it contains no meat at all, though I confess I am unsure of the ingredients of hoisin sauce.
(with apologies for the residue from a dropped onion piece on the table)
No substituions, though I did cut the recipe in half and I might have messed up a few of the relative proportions. In any case, this was very good. My chopstick skills need more practice; I gave up the painfully slow process about 1/2 way through my first bowl-full.