Onion is a bulbous herbaceous plant, already cultivated by the Egyptians, since then it started to be used in the kitchen. Onion bulbs are usually globular, mostly spherical in shape, but sometimes also flattened and elongated. They are composed of many closely overlapping fleshy leaves, which can vary from white to yellow, up to reddish. The bulb is externally covered by a thin, almost paper-like film, which must always be removed before use.
There are many varieties of onions that differ in color, size and shape but also in ripening and harvesting period. Among the many varieties: the Bianca di Maggio, large and flattened, the Bianca tonda di Chioggia, the Valenciana, the copper one from Milan with reddish skin and spinning top shape, the yellow golden one from Parma, with slightly flattened spherical bulbs and finally the Rossa of Tropea.
Among the small onions, also suitable for pickling: the Precoce di Barletta and the Giallognola di Como (their bulbs do not exceed 3 cm in diameter). Finally, there is the whole variety of spring onions, harvested when they are not fully ripe. These types have small, slightly oval bulbs, which continue in long hollow green leaves.
The use of onions in the kitchen is vast: indispensable in sautéing, excellent boiled and simply seasoned with oil and vinegar, stuffed and cooked in the oven, used raw in salads, fried, glazed in a pan or in meat stews.
As for the purchase, make sure that they are firm and compact, free of spots and with a slightly crunchy skin (in yellow or red onions) or shiny (in white ones). Keep them in a cool, dry and dark place, avoiding keeping them in the fridge, otherwirse they would mold and smell.
Onions have only a small disadvantage: when peeled raw, they make you cry (due to certain released substances). This problem can be solved by soaking them in a basin full of water or by keeping them in the fridge for 10 minutes. Also, while you clean them, wet the knife often. Beware of those suffering from gastric disorders since onions could irritate their stomachs.
The different varieties of onions
The varieties on the market are many and differ from each other in shape, size and color:
- Blonde: it is one of the most common and tastiest, perfect for sautées and soups.
- Bianca: it has a delicate flavor, either boiled or stewed. It is also ideal in pizzas and savory pies.
- Red: the best known variety is Tropea Igp. It is eaten raw and is also delicious in fillings and fish main courses.