King Oyster mushrooms, also known as king trumpet mushrooms or French horn mushrooms, are native to the Mediterranean regions of Europe, the Middle East, and Africa and are cultivated widely throughout Asia, where they're popular ingredients in Chinese, Japanese and Korean cuisines. Their dense, chewy texture makes them a popular substitute for meat and seafood.
King oyster mushrooms grow to 8 inches long and 2 inches in diameter, with thick, meaty stems. They have bright white stalks and tan or brown caps. Unlike many mushrooms, whose stems become tough and woody, king oyster mushroom stems are firm and dense but completely edible. Indeed, slicing the stems into rounds and sautéeing them yields something resembling sea scallops in texture and appearance, which is why they're sometimes referred to as "vegan scallops."