Prep the chicken – Wash and pat dry your chicken breasts. You can also trim off any excess fat from the chicken breasts.
Make the rub – In a small bowl combine onion powder, garlic powder, dried thyme, dried oregano, sage, black pepper, cayenne pepper, mustard powder, paprika, celery seeds, and salt. Mix until well combined.
Season the chicken – Next rub your chicken breasts with olive oil, followed by the seasoning. Make sure the chicken breasts are well coated with the seasoning.
Marinate in the refrigerator for at least 30 minutes or up to 4 hours to allow the flavors to penetrate the meat. Once the chicken has marinated, remove it from the refrigerator and let it sit at room temperature for about 10 minutes before grilling. This allows for more even cooking.
Prep the grill – Prepare your Traeger Pellet Grill by filling the pellet hopper with your preferred wood pellets such as applewood or hickory. Preheat your pellet grill to 375 F (190 C). This may take about 10-15 minutes. Lightly oil the grill grates to ensure the chicken breasts don’t stick.
Cook the chicken – For extra flavor, you can sprinkle additional spices or herbs over the chicken breasts just before grilling. Place them directly on the preheated grill grates. Close the lid and grill the chicken breasts for about 20-28 minutes flipping them halfway. The internal temperature should reach 165 F (74 C). To ensure juicy chicken breasts, do not overcook them.
Let it rest – Once the chicken breasts reach the desired internal temperature, take them off the grill and transfer them to a plate or a cutting board. Tent the chicken breasts loosely with aluminum foil and let it rest for 5 minutes to allow the juices to redistribute resulting in more tender and juicy chicken.