Heat olive oil in a large skillet over medium-high heat.
Season the chicken slices with chili powder, cumin, garlic powder, salt, and pepper.
Add the seasoned chicken to the skillet and cook for 5-7 minutes until browned.
Remove the chicken from the skillet and set aside.
In the same skillet, add the sliced bell peppers and onions.
Sauté the vegetables for about 5 minutes until they are tender.
Return the chicken to the skillet and mix with the vegetables.
Cook for an additional 2-3 minutes to heat through.
Serve the chicken and vegetables in warm tortillas.
Add your favorite toppings such as salsa, guacamole, or cheese.