01 - Preheat oven to 400°F. Lightly grease a large baking dish with cooking spray or additional oil.
02 - Arrange sliced onions and half the lemon slices evenly across the bottom of the baking dish to form a bed.
03 - Pat chicken breasts dry with paper towels and place on top of the onion and lemon layer.
04 - In a small bowl, whisk together olive oil, melted butter, minced garlic, oregano, thyme, salt, and black pepper until thoroughly combined.
05 - Brush or spoon the herb butter mixture evenly over all chicken breasts, ensuring complete coverage.
06 - Pour chicken broth into the dish around the chicken, not directly over it. Top each breast with remaining lemon slices.
07 - Cover dish tightly with aluminum foil. Bake for 25 minutes to steam and tenderize the chicken.
08 - Remove foil and continue baking for 15 additional minutes until chicken reaches internal temperature of 165°F and develops golden color.
09 - Remove from oven and let chicken rest for 5 minutes to redistribute juices. Sprinkle with fresh parsley before serving.