Soybean sprouts
Sprouted yellow soybeans with a large yellow bean head and a long, crisp stem, nuttier and sturdier than ordinary bean sprouts.
Caution: Soybean sprouts are not eaten raw but always cooked for a few minutes.
What supermarkets sell as bean sprouts is almost always mung bean sprouts; true soybean sprouts with the large yellow head are found fresh in Asian grocery shops, usually in the chilled section. They keep only a few days and should be firm and pale, without brown spots.
Substitute:
Mung bean sprouts will do at a pinch, but they are more delicate and watery and lack both the nutty flavour and the firm head; they need a much shorter cooking time.