Heat oil in a frying pan or skillet over medium-high heat. Add chicken, chili powder, cumin and salt. Stir to combine. Let chicken cook for 8 to 10 minutes or until cooked through. Remove from pan and set aside.
To the same pan, add peppers and onions. Stir to coat. Cook for 5 minutes or until peppers are tender.
Divide chicken and peppers between tortillas. Enjoy!