Onions are an indispensable flavouring in many savoury dishes. Widely grown in the UK, they are picked and allowed to dry out slightly until their skins are crisp and papery. Larger Spanish onions are much milder. White skinned onions are mild and sweet, as are red onions with their purple, papery skins; both are mild enough to eat raw in salads and can also be cooked (though red onions retain little of their colour).
Small, brown-skinned, white-fleshed onions, sometimes known as button onions, are good for pickling and adding whole to stews and casseroles. Silverskin onions, also known as cocktail onions, are usually pickled in jars. Shallots – although very similar to onions – are small and oval. Their flavour can be either sweeter or stronger, depending on how they were grown. Banana shallots are simply longer and thinner varieties.
Ensure onions are firm, have thin papery skin and show no signs of dampness or sprouting.
Peel off the papery skin of the onion and then chop, slice or grate as required. Brown onions have a pungent aroma that can make the eyes water. If you want to fry onions, don’t chop them in a food processor as this makes them watery and they will steam rather than fry. Fry or sauté onions in a little vegetable oil or butter until softened (or place chopped onion and oil in a covered microwave-proof bowl and cook on high for a minute or two). Onions brown quickly as they contain natural sugars that begin to caramelise when fried, creating a lovely savoury sweetness. Whole onions can also be roasted, stuffed, made into the classic French onion soup, or battered to give crisp fried onion rings.
Watch our video on how to chop an onion.
Keep onions in a cool dark place for up to 1 month. Do not store in the fridge as the smell will permeate everything.