Crush the chili pequins with a hammer and add half of them to ½ cup of boiling water. Boil for 4 minutes, turn off the heat and let sit for 5 minutes. Drain the water into a bowl and throw away the boiled pequins.
Put all of the other ingredients, including the remaining chili pequins and water, into a blender and blend. Add coarse kosher salt and fresh-ground pepper. Let the sauce sit in the fridge overnight before serving.