Preheat the broiler. Place hot peppers and garlic on a baking sheet or a piece of tinfoil. Broil for about 5 minutes, or until the peppers begin to char.
Transfer peppers, garlic, and all remaining ingredients to a food processor or blender. Process until smooth. Allow to cool completely at room temperature before use.
Notes
I left the pepper seeds in my sauce. For a milder - but still very spicy - version, you can remove and discard the pepper seeds before roasting.