Oyster sauce 蚝油 (háo yóu)

This thick brown sauce made from oysters, brine, and sugar has a light, salty taste and is used as a condiment and frequently added to stir fries to enhance flavor. It is sold in bottles in the Asian food aisle of the supermarket.

Noodles 面条 (miàn tiáo)

Chinese cooks use a variety of noodles. The chewy texture of fresh round noodles is great in soups in which you want the noodles to soak up flavor; fresh noodles can be purchased at Asian grocery stores. Japanese udon noodles are a good substitute for fresh noodles. Dried Asian egg and rice noodles can be bought at most supermarkets and stored unopened for up to 1 year.

Napa cabbage 大白菜 (dà bái cài)

This hearty cabbage originating in northern China has long white, tightly packed leaves with pale green tips. It is an excellent source of potassium, folic acid, and vitamin A. It is also known as Chinese cabbage. You may substitute savoy cabbage.

Mung bean sprouts 绿豆芽 (lǜ dòu yá)

The crunchy sprouts of germinated mung beans have the green buds still attached. Choose sprouts that are crisp and dry; avoid wet or slimy-looking ones. Fresh mung bean sprouts are available at most grocery stores, but you can also easily grow your own. Soak 1 cup of mung bean seeds overnight in water, then drain and place them in a large bowl covered by a damp towel. Rinse the seeds twice a day for 4 to 5 days, or until the sprouts grow to 3 inches long. Fresh bean sprouts will keep for up to 2 weeks in a sealed container. Soybean sprouts are a good substitute. Find them at Asian grocery stores or health food stores.

Mung bean flour 绿豆粉 (lü dòu fěn)

This is a very fine flour made from ground mung beans. Dough made with the flour turns translucent when cooked. It is used in making glass noodles and various pastries. Find the flour at Asian grocery stores.