In a large Dutch oven, heat olive oil and butter over medium-high heat until shimmering. Add diced chicken thighs with a pinch of salt and sauté for about 3 minutes until slightly browned and cooked through. Toss in finely chopped onion, cooking until it turns translucent and fragrant, about 2 more minutes.

Stir in chopped yellow, red, and orange bell peppers, along with minced garlic. Sprinkle in flour and all the spices and cook for 2 minutes, allowing the spices to bloom and fill your kitchen with their warm aroma.

Pour in low-sodium chicken broth, followed by black beans, long-grain white rice, and diced green chilies. Add crushed tomatoes, stirring to combine. Bring to a gentle boil, then reduce heat to low and let simmer, covered, for 30 minutes.

After 30 minutes, remove the pot from heat and stir in shredded pepper jack cheese until melted and creamy. If the soup feels too thick, gradually add a bit more chicken broth to reach your desired consistency.

Ladle the Chicken Fajita Soup into bowls, inviting everyone to add their preferred garnishes such as tortilla chips, fresh cilantro, sour cream, diced avocados, and a squeeze of lime juice. Enjoy!