Instructions:
1. Heat a heavy skillet or griddle over medium-high heat. Meanwhile, remove stems and seeds from chiles while rinsing under cold running water.
2. Place them on griddle and toast, three or four at a time, just until the aroma is released, about 30 to 60 seconds. Be careful not to burn them.
3. Place the chiles in a bowl and cover with hot water. Let soak until softened, about l0 minutes. Drain chiles and discard liquid.
4. Place chiles, oregano, 2 garlic cloves, and 2 cups of water or stock in blender and puree until smooth. (Add more stock if mixture turns is too thick for the blender.)
5. With a wooden spoon or pusher, work the puree through a sieve into a bowl, pushing and scraping to get all the solids. You may want to pour in a little more liquid to help rinse the sauce through the sieve.
