Tomatillo Sauce

1 pound fresh tomatillos, husked
1 cup chopped onion
1 cup vegetable stock
4 teaspoons minced garlic
1 tablespoon minced serrano chili
1/4 teaspoon cider vinigar
pinch of ground cumin
pinch of sugar
1/2 cup chopped fresh cilantro
salt

Preheat the oven to 350F.

On a parchment lined baking sheet, roast the tomatillos for 30 minutes
(I just nuked them in the microwave) or until very soft, but not split.
Coarsely chop them.

In a large saucepan, combine the tomatillos, onion, vegetables stock,
garlic, chili, vinegar, cumin and sugar.  Bring to a boil.  Reduce the
heat and simmer, covered, for 20 minutes.  Add the chopped cilantro and
transfer to a blender or food processor.  Puree until smooth.  Season to
taste.