Created by Sue on July 24, 2013
Step 1: Core tomatoes and blanch 1 minute, then plunge into ice water and slip off skins.
Step 2: Peel off tomatillo husks and rinse.
Step 3: Coarsely chop tomatoes, tomatillos and onion and add to a saucepan along with garlic, and seeded peppers. Stir in chipotles, adobo sauce, salt, cumin seed, vinegar and water.
Step 4: Bring mixture to a boil, then reduce heat and simmer until onion is soft, about 20 minutes. Allow it to cool.
Step 5: Puree mixture in batches in a blender or food processor until smooth.
Step 6: Return sauce to pan and cook until mixture is as thick as you like, maybe another 15 minutes or so, keeping pan covered with a lid vent open or using a splatter screen.