The chow mein sandwich, a strange specialty of drive-ins, diners, and cafes on the south coast of Massachusetts and Rhode Island east of Narragansett Bay (as well as at Nathan’s of Coney Island), exists because Frederick Wong started the Oriental Chow Mein Company in 1926. Genuine chow mein sandwiches are built with noodles the family makes at the old building in Fall River. These noodles are crunchy, not soft as in chow mein elsewhere. And traditional chow mein sandwiches are meatless: simply noodles topped with sauced sprouts all on a plate along with a hamburger bun.
For those more familiar with typical Chinese-American chow mein, the concept is a little weird. It is certainly not a sandwich you can pick up and eat, and while a bun floating in chow mein at first seems anomalous, an eater soon discovers that it is a mighty handy tool for mopping up the last of the gravy from the plate.