Place the chilies into a food processor along with 2 tablespoons of water, and pulse chop them into a coarse paste.
Add the chilies to a saucepan, then heat on medium for 3 to 5 minutes.
Add the vinegar and salt and stir to combine.
Continue heating for 10 minutes while stirring frequently.
Remove from heat and allow the sambal oelek to cool to room temperature. Serve immediately or refrigerate overnight for best flavor.
Video
Notes
For a medium heat paste, use Fresno peppers or serrano (double+ the heat of Fresno). For an extra fiery paste, use Thai chilies.Use gloves when handling any chili, especially Thai peppers.