Hi DO, just chop into rings then boil white whine vinegar or whatever for few mins, dissolve sugar and salt add water to dilute the mixture.
Then add rings and bring back to the boil until rings darken, then add to a jar.
Let cool and place in fridge and enjoy
Can be eaten straight away when cooled.
Total process about 10 mins boil chillies for 5 mins till darken green.