Finely slice a few handfuls of Thai red chillies (including seeds). Discard the stems and caps.
Place the slices and seeds in a plastic pint container with lid (you can re-use a small food container like for hummus or cream cheese).
Pour 1 cup of your vinegar of choice into a small saucepan: sweet rice vinegar, white vinegar, or black vinegar. Sprinkle in whole black peppercorns and/or szechuan peppercorns.
Bring the vinegar and peppercorns to a boil and turn off the heat. Pour the vinegar and peppercorns into your chilli container, covering the chillies with liquid. Cover with the lid and let it sit until room temperature.
Mark the name and date on the container, and refrigerate.
Use anytime as a garnish to add quick pickle heat!