How to Make It
Combine the first 5 ingredients in a medium saucepan. Cover, and cook over medium-low 25 to 30 minutes or until tender, stirring occasionally.
Transfer chile mixture to a blender; add 1/4 cup warm water and fish sauce. Remove center piece of blender lid (to allow steam to escape); secure lid on blender, and place a clean towel over opening in lid. Process until smooth; add up to 3 tablespoons more water, 1 tablespoon at a time, if necessary. Serve immediately, or refrigerate in an airtight container up to 7 days.