Roast the chilies in oven @ 350 on a cookie sheet for 15 minutes.Remove and place in a paper bag for 10 minutes.Remove from bag and discard the stems and seeds.
Place all ingredients in a saucepan and simmer for 15 minutes.
Pour into a blender one cup at a time and puree. Strain sauce through a sieve into a bowl, mashing with the back of a spoon. Discard solids. If sauce is too thin, place back in saucepan and reduce to the consistency of a thick tomato sauce.
Serve warm over enchiladas or burritos, topped with shredded cheese.