1. Heat the olive oil in a skillet over medium heat.
2. Add the chicken breast and cook until no longer pink, about 7-8 minutes per side.
3. Remove the chicken from the skillet and shred it using two forks.
4. Return the shredded chicken to the skillet and add chili powder, cumin, garlic powder, and onion powder. Stir to combine and cook for another 2-3 minutes.
5. Warm the tortillas in a separate skillet or microwave.
6. Assemble the tacos by placing the chicken mixture on the tortillas and topping with shredded lettuce, diced tomatoes, and shredded cheese.