Grill the Chicken: Pound chicken breasts to even thickness. Season with salt, pepper, and garlic powder. Grill or pan-sear over medium-high heat until cooked through (internal temp 165°F).
Prepare Ranch Spread: Mix ranch dressing and Parmesan. Set aside.
Make Parmesan Crust: Mix panko, shredded cheeses, and melted butter in a bowl. Stir until crumbly.
Assemble and Broil: Place cooked chicken on a baking tray. Spread ranch-Parmesan mixture on each piece. Top generously with the Parmesan crust mixture. Broil for 2–3 minutes until golden and bubbly. Watch carefully so it doesn’t burn.
Serve: Garnish with parsley if desired. Serve with mashed potatoes, seasoned rice, or steamed veggies like broccoli.