In a bowl, combine olive oil, lime juice, chili powder, cumin, garlic powder, onion powder, salt, and black pepper. Add the chicken strips and toss to coat. Marinate for at least 15 minutes.

Heat a skillet over medium-high heat. Add the marinated chicken and cook for about 5-7 minutes, or until cooked through and no longer pink.

In the same skillet, add the sliced bell pepper and onion. Sauté for 3-5 minutes until they are tender but still crisp.

Serve the chicken and vegetables in warmed tortillas, topped with sour cream, shredded cheese, and salsa if desired.