It looks like a small, oval orange, but the kumquat, which originates in Asia, is a member of another species, fortunella.
The flesh of a kumquat is quite dry and has a sharp flavour, while the skin is sweeter; the two different flavours complement each other well so that the fruit succeeds in both sweet and savoury dishes.
The rind, flesh and pips of kumquats are all edible, though some people prefer to remove the pips.
All year round.
Choose the best
Look for firm fruits with no discolouration and a soft sheen.
Wash, pull off the stem, then chop or slice as required. The thin skin is very tricky to peel and, as it provides a pleasant contrast to the slightly more sour flesh, it's generally left on.
Kept in the fridge in a perforated bag kumquats can last for up to two weeks.
If very ripe, eat whole or slice to use in salads. Less ripe fruit can be simmered in sugar syrup (30 minutes) before being added to fruit salads, or served with ice cream. You can also use it to make marmalade.
Try orange or clementine.