Step 1

Bring the water to a soft boil and immediately remove from the heat.

Step 2

Add the sugar and stir until dissolved.

Step 3

Slice the onion into thin rings or strips.

Step 4

Mix the sugar-water with the vinegar, salt, oregano and peppercorns.

Step 5

If you'd like the onions to be spicy, add in strips of habañero, serrano or jalapeño peppers.

Step 6

Put the onions in a tupperware or lidded jar (with around 3 cups capacity), cover with the mixed liquid and give it a good stir.

Step 7

Close the container or jar and leave to marinate in the fridge for at least 2 hours, preferably overnight.