In a medium saucepan, simmer the chicken stock and chiles over medium-high heat until the chiles are very tender, about 15 minutes. Using a food processor or blender, puree the stock and chiles.
In a large skillet, heat the EVOO, 2 turns of the pan, over medium-high heat. Add the onion and garlic and cook until tender, about 5 minutes. Add the sherry and cook for 1 minute to burn off the alcohol. Add the chicken, ancho puree, cumin, coriander, paprika, oregano and cinnamon and cook until heated through, 3 to 4 minutes.
Spoon the chicken mixture into the tortillas and serve with the guacamole and pico de gallo.