In a saucepan, tost off the cloves and peppercorns for a few minutes.
Add in the water, vinegars, and brown sugar and heat until the brown sugar is dissolved.
Sterilize your jar and then add in a quarter of the onions, top with a bit of the salt and repeat until all your onions and salt are in there, you may need two jars.
Top with the pickle brine and then let cool before you screw on the lid. Once cooled add to the fridge overnight and they will be ready.