Directions
In the basin of a 6-quart or larger slow cooker, spread the sliced bell peppers and onions in an even layer.
Place the chicken breasts on top of the vegetables.
Pour the can of undrained diced tomatoes and green chiles over the chicken.
Sprinkle evenly with the cumin, red pepper flakes, salt, and pepper.
Cover and cook on LOW for 3 to 4 hours, or on HIGH for 1. 5 to 2 hours, until the chicken is fully cooked and tender enough to shred. The internal temperature should reach 165°F (74°C).
Carefully remove the chicken breasts and place them on a cutting board. Use two forks to shred the chicken, or slice it into strips if you prefer. Return the chicken to the slow cooker and stir to combine it with the vegetables and juices.
Serve the fajita mixture warm in tortillas, accompanied by your favorite toppings.