In a small bowl, mix together the smoked paprika, cayenne pepper, thyme, garlic powder, onion powder, black pepper, oregano, and salt to create the blackened seasoning.
Pat the chicken breasts dry with paper towels and brush lightly with oil.
Coat both sides of the chicken with the blackened seasoning, pressing it in for maximum flavor.
Heat 1 tbsp oil in a cast-iron skillet over medium-high heat until smoking slightly.
Add the chicken to the skillet and cook undisturbed for 5 minutes to develop a blackened crust.
Flip and cook for another 5 minutes, or until the internal temperature reaches 165°F (75°C).
Remove the chicken from the skillet, cover loosely with foil, and let it rest for 5 minutes.
Serve whole or slice over pasta, salads, or sandwiches.