All the smoky-sizzling flavors of classic fajitas in a cozy soup: tender chicken, rainbow bell peppers, garlic, and tomatoes simmered in seasoned broth with a creamy option. One pot, weeknight-friendly, and perfect for toppings like cilantro, avocado, shredded cheese, and tortilla strips.
Heat a large pot or Dutch oven over medium heat. Add olive oil and warm until shimmering.
Add diced onion and a pinch of salt; sauté until translucent and lightly softened, about 3–4 minutes.
Stir in red, green, and yellow bell peppers plus minced garlic. Sprinkle in fajita seasoning and ground cumin; cook 60–90 seconds to bloom the spices.
Push vegetables to the sides and add the chicken to the center. Season with salt and pepper. Cook, stirring, until chicken is opaque on the outside, 3–4 minutes (it will finish cooking in the broth).
Pour in chicken broth and the can of diced tomatoes with their juices. If using, add rinsed black beans and frozen corn. Stir to combine and bring to a gentle boil.
Reduce heat to maintain a steady simmer. Partially cover and cook 15–20 minutes, until chicken is cooked through and peppers are tender.
For a creamy version, stir in heavy cream or unsweetened coconut milk. Simmer gently 3–5 minutes (do not boil vigorously after adding dairy or coconut milk).
Taste and adjust seasoning with more salt, pepper, or fajita seasoning as needed. Squeeze in fresh lime juice to brighten.
Ladle into bowls and garnish with chopped cilantro. Add desired toppings such as shredded cheese, avocado slices, tortilla strips, or a small dollop of sour cream. Serve with extra lime wedges.