Place chiles in a small bowl or liquid measuring cup and cover them with boiling hot water. Place plastic wrap over the top to trap the steam. Allow peppers to sit for 15-30 minutes or until peppers are soft.
Remove the peppers from the water, set water aside but do not discard. Cut off the stem and scrape the seeds out.
Place rehydrated peppers and about 1 Tablespoon of water that chiles were soaking in in a blender. Blend until the consistency of pureed baby food is achieved. Add additional water if needed, but be cautious to not add too much water to dilute the puree. At this point you may add additional seasonings and spices if desired.
Notes
Transfer to an airtight container and store in the refrigerator. Will last for a couple of weeks.