Scallion, green onion, spring onion and salad onion are English names (with many other regional names throughout the world) for various Allium species. All of the Allium have hollow green leaves (like the common onion), but these are used while they lack a fully developed root bulb. Used as a vegetable, they are eaten either raw or cooked. Scallions have a milder taste than most onions.
The words scallion and shallot are related and can be traced back to the Greek ασκολόνιον ('askolonion') as described by the Greek writer Theophrastus. This name, in turn, seems to originate from the name of the ancient Canaan city of Ashkelon. The plant itself came from farther east of Europe.
Species and cultivars which may be called "scallions" include:
Spring onions may be cooked or used raw as a part of salads, salsas, or Asian recipes. Diced scallions are used in soup, noodle and seafood dishes, as well as sandwiches, curries or as part of a stir fry. In many Eastern sauces, the bottom half-centimetre (quarter-inch) of scallions roots is commonly removed before use.
In Mexico and the Southwest United States, cebollitas are scallions that are sprinkled with salt and grilled whole and used with cheese and rice. Topped with lime juice, they typically serve as a traditional accompaniment to asado dishes.
In Catalan cuisine, calçot is a type of onion traditionally eaten in a calçotada (plural: calçotades). A popular gastronomic event of the same name is held between the end of winter and early spring, where calçots are grilled, dipped in salvitxada or romesco sauce, and consumed in massive quantities.
In Japan, scallions are cultivated in two separate ways. In Western Japan, "leaf" green scallions are typically consumed, where the green portion is consumed. In Eastern Japan, "root" green scallions are popular. The scallions are partially buried, so a portion of the stalk is kept underground. As a result, a significant part of the stalk remains white in color, and has been cultivated to be very thick. The green portion of these "root" scallions are discarded, and the thick white portions of the scallion are consumed. In Japanese cuisine, scallions are used in abundance, as an accompaniment to tofu, noodle dishes, hot pots, and stir fries.