I got this recipe by way of JimJim, who found out we liked pickled onions and made it for Saturday Supper.
Take red onions, lime juice, salt, and peppercorns.
Mix one teaspoon of salt per cup of lime juice, then slice your onions into about quarter-inch wide slabs, and bust the slabs into individual rings.
Put a small pinch of peppercorns into a Mason jar, stuff it full of rings of onion, cover with lime juice/salt, and bung it into the fridge for a day or so.
The peppercorns aren’t part of JimJim’s original recipe, but I think it adds a nice extra tang — feel free to leave them out.
After a day or two of marinating, serve with a nice, strong cheddar cheese, or catfish, bangers, BBQ, or hell anything.
Should be good for a couple of weeks in the fridge, but if you like pickled onions I don’t think you have to worry about shelf life.