Whisk together oil, lemon juice, and all the spices.: The first sensory gift is the bright citrus aroma mingling with the warm scent of paprika and garlic powder as you whisk. You should see a glossy, slightly emulsified mixture where the oil suspends the spices evenly. This matters because a uniform marinade ensures every bite has balanced flavor. If the mixture separates, whisk again vigorously to recombine. A common mistake is under whisking, which leaves pockets of salt or concentrated spice that can unevenly season the chicken .
Place chicken in a gallon ziplock bag. Lightly pound the chicken with a meat mallet or rolling pin to an even thickness. Pour marinade over chicken.: When you press the meat to even thickness, you will hear a soft thud and feel the fibers relax under the mallet. The surface should be slightly flattened but not shredded. Even thickness guarantees consistent cooking so the interior hits 165ºF at the same time as the exterior browns. After adding the marinade, massage the bag gently so the liquid hugs each piece. Avoid over pounding which can make the texture mushy, and be careful not to overfill the bag to prevent leaks.
Refrigerate chicken overnight.: As the chicken rests chilled, aromas will deepen and the lemon will tenderize the outer layers. Overnight allows flavors to penetrate the meat for a fuller taste the next day. The fridge keeps the process safe, and you should notice a slightly plumped texture as the proteins relax. Do not leave the meat out at room temperature while marinating, as that invites bacterial growth. If you are short on time, even a few hours will help, but the overnight rest is ideal for best flavor.
Remove chicken from marinade 1 hour before grilling. Discard marinade.: Bringing the chicken out of the fridge an hour before cooking lets it come closer to ambient temperature so it cooks more evenly and develops a better crust. You will notice the chill easing and the surface becoming less cold to the touch. Discarding the used marinade prevents contamination and avoids greasy flare ups on the grill. A common slip is to reuse leftover marinade without boiling it first, so always discard or properly cook any leftover marinade.
Prepare grill and grill chicken until done, approximately 12 to 15 minutes, until chicken reaches an internal temperature of 165ºF.: When the breasts hit the hot grill or a preheated cast iron pan, listen for a steady sizzle and watch the edges begin to caramelize into golden brown with occasional darker char spots. Flip once to develop crosshatch marks and even crust, and check internal temperature with a reliable meat thermometer. This technique seals juices while producing Maillard browning that enhances flavor. If the heat is too high you may get burnt exterior and undercooked centers, so aim for medium to medium high and move pieces to cooler zones as needed. The most frequent error here is flipping too often, which prevents good crust formation, so let each side form color before turning.