Combine chiles in adobo sauce, additional adobo sauce, lime juice, lime zest, sour cream, cilantro leaves, cumin, and garlic in a a food processor or blender, and puree until a sauce has formed. Set aside.
Slice bell peppers into strips and set aside.
Slice chicken breasts into 1-inch bite-sized chunks.
In a large bowl, add bell peppers, 1 tbsp light oil, 2 tsp fajita seasoning, and ½ sauce mixture. Toss to coat evenly.
Transfer seasoned peppers to a large nonstick or stainless steel skillet. Heat on medium-high until the peppers become soft and maleable, about 8-12 minutes. Remove and set aside.
In a large bowl, add sliced chicken, remaining 1 tbsp light oil, remaining 2 tsp fajita seasoning, and remaining ½ sauce mixture. Once again, toss to coat evenly.
Transfer seasoned chicken to the same heated skillet. Heat on medium-high until the chicken is cooked through and most liquid has evaporated from the pan, about 10-15 minutes. Remove and set aside.
Assemble your fajitas on a flour tortilla with shredded cheese, creamy jalapeno sauce, sour cream, guacamole, or your favorite soft taco topping.
