Onion

Slice them evenly and cook slowly in a wide pan with a little oil or butter over low to medium-low heat, stirring often. Allow about 30–45 minutes for deep golden, soft onions; lower the heat if they start catching.

Use a sharp knife and chill the onion for about 15 minutes before cutting. Leave the root end intact until last, as it releases more of the compounds that make your eyes water.

Keep whole onions in a cool, dry, dark place with good air circulation, rather than in a sealed bag. Refrigerate a cut onion in a covered container and use it within a few days.

Yes. Peel and chop them, then freeze in a sealed container or bag; they may soften when thawed, so use them straight from frozen in soups, stews and other cooked dishes.

Red onions are popular raw in salads and sandwiches because their colour and sharpness stand out; soaking sliced red onion briefly in cold water can mellow it. Yellow onions are a versatile choice for soups, stews and slow cooking.

Use sliced leek or chopped shallot in soups, sauces and cooked dishes. Leek has a milder flavour, while shallot is more delicate and sweet; start with a similar volume and adjust as you cook.

Onions form the aromatic base of many soups, stews, curries and sauces. They are also the star of French onion soup, and sliced onions are often battered and fried as onion rings.

A firm onion with a small green shoot is generally fine to eat; remove the shoot if you find its flavour too strong or bitter. Discard onions that are mouldy, slimy or soft throughout.