Saut? minced onions and garlic slowly in a heavy pan over low heat until very soft and starting to brown -- about 10 minutes. Stir in flour and cook until it begins to foam. Add green chilies, chicken stock and cumin, bring to a boil and then reduce to a simmer, cooking down to a sauce, about 10 minutes longer. Use to smother burritos, enchiladas, grilled meats or any southwestern favorite.