Preheat skillet over medium heat. Add oil, then onions and garlic. Saute for 4-5 minutes or until starting to soften and translucent. Add cumin; saute for a minute or so. Sprinkle flour over onion mixture, cook and stir for a minute or two. Slowly stir in chicken broth until no flour clumps remain. Cook, stirring occasionally, for another five minutes or so until mixture is hot and thickened.
Add chiles, oregano, sauce from skillet and jalapeno (if using; consider adding a small amount of pepper until you reach desired heat level) to a high-powered blender (such as a Vitamix). Process on high until smooth. Season well with salt and pepper.
Mothers Secret Recipes of Comfort Food & Culinary Inspiration from an Organic and Allergen-free Approach