Begin by preparing the seasoning blend. In a small bowl, combine the chili powder, cumin, garlic powder, paprika, oregano, salt, and pepper. Stir until thoroughly mixed and set aside.

Generously coat both sides of the chicken breasts with the prepared seasoning. Press the spices in firmly with your fingers so they adhere well to the surface of the meat.

Heat the olive oil in a large skillet over medium heat. Place the chicken in the hot pan and sear for 7 to 8 minutes per side, or until fully cooked and golden brown on the outside. Once done, transfer the chicken to a plate and let it rest briefly.

While the chicken cooks, thinly slice the bell peppers and onion. After removing the chicken from the skillet, add the sliced vegetables to the same pan. Sauté over medium heat for 4 to 5 minutes, stirring frequently, until softened and slightly caramelized.

Slice the rested chicken into strips. For thinner pieces, halve the strips lengthwise.

Return the sliced chicken to the skillet and mix it with the sautéed peppers and onions. Finish with a fresh squeeze of lime juice, stirring to combine all the flavors.

Serve the hot chicken fajitas with warm tortillas and your favorite toppings like sour cream, pico de gallo, or creamy avocado slices.