In a small bowl, combine the minced garlic, smoked paprika, dried oregano, salt, onion powder, paprika, black pepper, and cayenne pepper. Whisk these dry and aromatic ingredients together to distribute the spices evenly, which ensures consistent flavor throughout the marinade. Add the fresh lemon juice and extra virgin olive oil, stirring until you have a cohesive, well-combined paste. I find that mixing the spices with the lemon juice before adding the oil helps them dissolve better and prevents clumping.

Place the pounded chicken breast into a resealable plastic bag or shallow dish. Pour the prepared marinade from Step 1 over the chicken, making sure every surface is thoroughly coated with the spice mixture. Seal the bag or cover the dish and refrigerate for at least 1 hour—this allows the flavors to penetrate the meat and the acid from the lemon juice to begin tenderizing it. I recommend marinating for closer to 2 hours if you have the time, as it develops deeper Cajun flavor without over-marinating.

Remove the chicken from the refrigerator about 10 minutes before grilling to bring it closer to room temperature for more even cooking. Heat your grill to medium-high heat (around 400°F). Place the chicken on the grill and cook for approximately 5-6 minutes per side until the internal temperature reaches 165°F when measured with a meat thermometer in the thickest part. The even thickness you pounded earlier ensures both sides cook at the same rate, giving you a nicely charred exterior while keeping the interior moist.