Dissolve the sugar in water, bringing it to the boil.
Add the sliced onion and simmer for 3-4 minutes.
Add the vinegar, pour over the peeled sliced (diced or cut into wedges) beet and leave to cool.
Beetroot: Leave 5cm (2 inch) of leaf stalks on top and the whole root on the beet.
Hold it under a running tap and wash off the mud with the palms of your hands, so that you don't damage the skin; otherwise the beetroot will bleed during cooking.
Cover with cold water and add a little salt and sugar.
Cover the pot, bring to the boil and simmer on top, or in an oven, for 15-20 minutes (in May/June when they are young) depending on size (they can take 1-2 hours in late Autumn and Winter when they are tough).
Beetroot is usually cooked if the skin rubs off easily and if they dent when pressed with a finger.
If in doubt, test with a skewer or the tip of a knife.
