01 - Preheat oven to 400°F. Lightly grease a baking dish large enough to arrange the tilapia fillets in a single layer.
02 - Pat tilapia fillets dry using paper towels. Place them in the baking dish and brush both sides lightly with olive oil.
03 - In a small bowl, whisk together melted butter, minced garlic, lemon juice, lemon zest, chopped parsley, salt, and pepper.
04 - Pour the lemon butter mixture evenly over the tilapia fillets, ensuring each piece is thoroughly coated.
05 - Place a lemon slice atop each fillet for added flavor.
06 - Bake for 15 to 20 minutes, until the fillets flake easily with a fork and are opaque throughout.
07 - Remove from oven and garnish with additional chopped parsley if desired. Serve immediately.