1 pound hot red chili peppers (Fresno, red jalapeño, cayenne, Thai, etc., or a mix of all of them)
1 red bell pepper (to tame heat, if needed)
1/4 cup distilled white vinegar (5% acidity)
1 tablespoon kosher salt
Cut hot chili peppers into smallish chunks, including green caps (but not stems).
Chop in a food processor to a chunky paste. Taste to determine heat. If it is too hot, add bell pepper a chunk at a time to lower the heat level. Continue to process to your desired heat level and consistency.
Mix in the vinegar and salt.
Put in a glass pint jar, attach top loosely, and let sit for a day at room temperature to develop the flavor.
Seal tightly and refrigerate up to several weeks.