This chicken fajita soup combines the vibrant, smoky flavors of traditional fajitas with the comforting warmth of a soup. This versatile dish is perfect for a cozy dinner, and can be easily adjusted to suit your preferences. To kick up the heat, add a chopped jalapeño to the veggie mixture. You can swap out the rotisserie chicken for another protein like leftover steak, or make it vegetarian by using no-chicken broth and subbing tofu in place of the chicken.