Seitan is a food made from wheat. Cooks wash the flour until the starchy part is gone and a stretchy protein mass is left; that mass is then cooked until it is firm and chewy. People who do not eat meat often use it instead of chicken or beef, because it takes up sauce and has a bite. The word is Japanese in origin and came into English with vegetarian and vegan cooking, especially from the 1960s on. It is not tofu — tofu is from soy — though beginners sometimes put both in one “not meat” pile. In Japan, ordinary wheat gluten is often called fu; seitan is the name this protein food took on in English, and you will also hear “wheat gluten” or “gluten meat” on packets. In a Taiwan kitchen you already know 麵筋; seitan is that wheat-protein food, usually prepared to stand in for meat, not the puffy fried balls in soup.

麵筋（當肉吃的小麥蛋白；不是豆腐）