Slice the onion into thin strips and cut the bell peppers into slices.
In a bowl, mix 1 tablespoon olive oil, juice of half a lime, chili powder, smoked paprika, onion powder, black pepper, cumin, and ½ teaspoon salt.
Cut the chicken into strips and toss with the seasoning mixture.
Heat 1 tablespoon olive oil in a pan over medium-high heat. Add half the chicken and cook for 3–5 minutes until fully cooked. Remove and repeat with remaining chicken.
In the same pan, add the remaining oil. Cook the onions for 2 minutes, then add peppers and remaining salt. Cook for another 2 minutes until slightly tender.
Return the chicken to the pan and stir well to combine.
Squeeze fresh lime juice over the Easy Chicken Fajitas and serve warm with tortillas.