Step 1

In a large pot, heat the oil and butter over medium heat. Add the onions, garlic, and green pepper and cook, stirring occasionally, until tender and just starting to brown, about 15 minutes. (Turn the heat to medium-low if the mixture is browning too quickly.)

Step 2

Add the flour and cook, stirring constantly, for 1 minute. Add the chicken broth, cut tortillas, cumin, chili powder, salt, and cayenne and bring to a boil. Turn the heat down to low and simmer, uncovered, for 15 minutes.

Step 3

Remove the pot from the heat, then use a handheld immersion blender to purée the soup until completely smooth. (Alternatively, let the soup cool slightly and use a blender to purée in batches. Be sure to remove the center knob on the blender top and cover with a dish towel to avoid splatters.) Taste and adjust seasoning, if necessary. Stir in the chicken, if using, then ladle the soup into bowls and serve with optional additions.

Step 4

Note: I usually use leftover or rotisserie chicken for this soup, but if you want to cook the chicken from scratch, you’ll need two bone‑in chicken breasts. Preheat the oven to 425°F and set an oven rack in the middle position. Place the chicken breasts on an aluminum foil–lined baking sheet, season with salt and pepper, and cook for 35 to 40 minutes, or until the chicken is cooked through. Let cool, then pull the meat off the bone and cut into bite-sized pieces.

Step 5

Freezer-Friendly Instructions: The soup can be frozen for up to 3 months. Defrost the soup in the refrigerator for 12 hours and then reheat it on the stovetop over medium heat until hot. This soup will also keep nicely in the fridge for 3 to 4 days. (If refrigerated or frozen, the soup will thicken up quite a bit, so add a bit of water or chicken broth while reheating to thin it out as necessary.)