The kitchen onion is an allium vegetable, named after the edible part – the onion – a group that also includes chives, garlic and leeks. The shape and size of onions vary considerably, ranging from disc-shaped to elongated and egg-shaped. The outer layers of the onion are membranous and come in various colours (white, yellow, purple, brown). The fruit is a capsule. This red onion has a slightly sweeter flavour and a reddish-purple skin.