Peel and thinly slice onions
Put pan of water to boil
Put vinegar, sugar, peppercorns and spices into small pan.
Heat gently until sugar is dissolved
Simmer for 2 mins and remove from heat.
Put onions into boiling water.
Boil for 1 minute
Drain well and leave to cool slightly
Pack into jar and pour over vinegar
Cool completely, make sure it is sealed.
Store chilled.