The main uses of Welsh onion include seasoning, removing fishy odors, and providing nutrition.

Welsh onion (Allium fistulosum) is a perennial herbaceous plant in the genus Allium of the lily family. It is also a popular vegetable with a long history of cultivation in China, and it is widely grown in both the north and the south. Its white stalk is thick and long, with a strong pungent aroma. It is not only an indispensable seasoning in home cooking, but can also be served as a dish on its own, and it has long been loved by people.

In cooking, the most important role of Welsh onion is to season and remove fishy odors. Whether it is used to heat oil and release aroma, to make scallion-ginger water, or to remove fishiness and enhance freshness from ingredients such as fish and meat, Welsh onion can produce an obvious aroma-enhancing effect. Classic dishes such as scallion-blasted lamb and braised sea cucumber with scallion both use Welsh onion as a main ingredient, and the finished dishes have a rich scallion aroma and a prominent flavor. In some northern regions, Welsh onion dipped in sauce and scallion rolled in pancakes are even very common ways of eating it.

From a nutritional perspective, Welsh onion contains components such as vitamin C, dietary fiber, and volatile oil. Its pungent odor mainly comes from the sulfur compounds it contains. Eaten in moderation, it helps increase appetite and promote digestion. When the weather turns cool, sprinkling a handful of chopped scallion on hot soup or noodles also often makes people feel especially appetizing and comfortable.

In folk tradition, Welsh onion is considered warm in nature and is often paired with ginger to dispel cold. Boiling the white stalk in water is also a common method used by many households to deal with discomfort from catching a chill. It should be noted that Welsh onion is pungent and stimulating, so it should not be eaten raw in excess, and people with weaker digestive systems should control the amount they eat even more to avoid discomfort.