To fill a 1litre Kilner jar you will need to buy around 800g of large Thai chillies such as these;
Slice down their length and scoop out the seeds with the wrong side of a spoon.
Place in the Kilner, fill with boiling water and leave for 5 minutes (this removes the rest of the seeds).
Drain and leave the chillies in the jar.
Add to the jar;
15 black peppercorns
5 bay leaves
2 tablespoons coriander seeds
5 teaspoons salt
Now (a la Jamie Oliver but with the sugar content much reduced), boil together the following ingredients;
4 heaped tablespoons caster sugar
1 litre / 1 3/4 pints white wine vinegar or rice vinegar
Allow to cool a bit and add to the jar.
Wait for the jar to cool to around hand hot and then close the lid and store for at least 2 weeks.