*available at some specialty foods shops and by mail from The Chile Shop, 109 East Water Street, Santa Fe, New Mexico, 87501 (505-983-6080)

In a large saucepan simmer the chilies, the onions and the garlic in the water for 20 minutes. Transfer half the chilies, the onion, and the garlic with tongs to a blender, add 3/4 cup of the cooking liquid, and puree the mixture until it is smooth. Force the puree through a sieve into a bowl, pressing hard on the solids with a spoon. Repeat the procedure with the remaining cooking liquid, stir in salt to taste, and discard the remaining cooking liquid. The sauce may be made 2 weeks in advance and kept covered and chilled.