Slice the tortillas into thin ribbons then place them in a food processor. Pulse them until uniformly chopped. Then add the flour, chili powder, cumin, salt, and pepper. Blend continuously until it is the consistency of cornmeal.

Place oil in stockpot set over medium-high heat. Add the onion, poblano pepper, jalapeno pepper (if using) and garlic. Turn the heat down to medium and sauté until the onion is transparent 6-8 minutes.

Add tortilla-flour mixture to the pan stirring until well combined. Add butter and let it melt. Then mix to form a roux-like chunky paste.

Cook 4-5 minutes stirring constantly with a whisk-. You want to get out any raw flour taste. But do not let mixture burn.

Once a thick chunky paste has formed stir, slowly adding the 1/2 of the broth and scraping down sides and bottom as you work. After half of the broth has been added continue to stir until you are sure all the powder are well incorporated. Then add the remaining broth and raise the temperature to bring the soup to a boil.

Add the corn cob-ettes (if using) and let them boil about 1-2 minutes.

Lower the heat to medium low and allow the soup to come to a simmer. Then add sour cream, and cook an additional 7-10 minutes. But do not allow the soup come to a boil.

Turn off heat and let cool a bit. This soup is best served warm, but not hot.

Garnish with shredded cheese and avocado.

Serve the chicken on the side to be added to the bowl as each diner sees fit.