In a medium sauce pan, sauté onion in olive oil over low heat until translucent, add garlic. In a blender combine tomatillos, green chili and stock, add to sauce pan and cook for 30 minutes. In a measuring cup mix 1/4 cup water and 2 T cornmeal until no lumps remain, add to sauce for thickening. Reduce heat and simmer for 15-30 minutes, while making burritos.
NotesWhen making with pork, saute the meat along with the onion and increase the simmer time to achieve the desired tenderness.