Add the fajitas seasoning ingredients to a small mixing bowl and stir together.
Generously sprinkle the fajita seasoning on both sides of the chicken and use your fingers press it into the chicken.
Heat the oil in a large skillet over medium heat. Sear the chicken breasts for about 7-8 minutes on each side. Then remove them from the pan and let the chicken rest for a few minutes before slicing into strips.
While your chicken is cooking, cut the bell peppers and onion into thin slices.
Once the chicken is removed, saute the bell peppers and onion in the same skillet over medium heat for 4-5 minutes, stirring frequently.
Add the chicken back into the skillet, add a squeeze of fresh lime juice and stir everything together.
Serve immediately with tortillas and extra toppings such as sour cream, pico de gallo and guacamole.