Seitan is a veggie foodstuff made from wheat gluten. I buy the Arrowhead mills mix and follow the directions. Mix seitan powerder (which the ingredients say is largely wheat glutten), kneed for a few minutes, let rest, cut into pieces (roughly 2 X 2 X 2) and simmer in a soy sauce, ginger, water and kombu broth for two to four hours. Kombu is a sea vegetable that forms the base of many Japanese soup stocks and its use in the broth is optional. The seitan can then be cut into thin strips and added to stir fries, stews or any other dish where you might use beef. Seitan is quite beef-like, but lighter and with a slightly different texture.
I mainly do two things with seitan--Seitan Stew and Seitan with Brown Sauce. I believe the Brown Suace is what often gets called a Sezchuan suace in Chinese-American restaurants.
The seitan stew basically comes from the recipe book in the Arrowhead Mills package. Saute a few chopped onions with garlic, and when soft or brown add a few cups of water and several cups of chopped vegetables (carots, potatos, parsnips, peas, ect) and the sliced sietan. Simmer untill the veggies are done; spice with thyme and parsely and perhaps thicken with a bit of cornstarch solution. Its an inexact recipe as most stew are, but satisfying on a cold day.
My basic brown (Sezchuan) sauce is a tablespoon of miso, a half a teaspon of sugar, a teaspoon or so of black bean suace or chili paste with garlic, a few tablespoons of soy sauce and some white vinegar--all thined out with about a half a cup of water. Stir fry garlic and ginger in sesame oil and add the usual suspects suspects (onions or leeks and maybe carrots, eggplant, or brocoli); add the sliced seitan toward the end. After all this is almost cooked, pour in the sauce and, if need be, thicken with cornstarch. Serve over rice, ladeling a bit more sauce and topping with green onions if you have them.