You will need
Tint with a few drops of red colouring if only ordinary brown onions are available.
Slice the halved onions very finely into half rings. Pour boiling water over and soak for 10 minutes. Drain and add orange and lime juices, as well as sliced chilli and Seasonings. Stir to blend everything very well. Leave to stand, well covered, in a glass or porcelain container. This relish will keep for up to a week in the fridge.