Pat the chicken breasts dry with paper towels, then season both sides generously with salt and black pepper. Rub the avocado oil evenly over all surfaces of the chicken, ensuring complete coverage. This oil layer will help prevent sticking on the grill and create a better sear. Set the seasoned chicken aside on a clean plate while you prepare the grill.

Preheat your grill to medium-high heat (around 400°F) with the grates clean and oiled. While the grill heats, combine the melted butter, 2 1/2 tsp garlic powder, freshly grated parmesan cheese, red pepper flakes, and fresh parsley in a small bowl. Stir well to create a smooth, fragrant sauce. I like to let this sauce sit for a minute so the garlic powder fully blooms in the warm butter—it intensifies the flavor significantly. Set the sauce aside until the chicken is cooked.

Place the oiled chicken breasts on the preheated grill and resist the urge to move them around—let them sear undisturbed for 5-7 minutes on the first side until golden grill marks form. Flip each breast carefully and grill the second side for another 5-7 minutes, until a meat thermometer inserted into the thickest part reads 165°F. I always use an instant-read thermometer because visual cues can be deceiving, especially with thicker cuts. The exact timing depends on the thickness and your grill's hot spots, so use the temperature as your guide.

Transfer the grilled chicken to a clean serving plate or cutting board. While the chicken is still hot, generously coat each breast with the garlic parmesan sauce from Step 2, using a brush or spoon to distribute it evenly. The residual heat will help the butter and cheese meld into the chicken beautifully. Let the chicken rest for 2-3 minutes—this allows the juices to redistribute, keeping the meat moist and tender when you slice or serve it.

Give the rested chicken a final drizzle of fresh lemon juice just before serving—the acidity brightens the rich butter and cheese flavors beautifully. Serve immediately while the chicken is hot and the sauce is at its best.