01 - Preheat the oven to 400°F. Line a baking dish with parchment paper or lightly grease it.
02 - Pat the fish fillets dry using paper towels. Season both sides evenly with salt and black pepper.
03 - Place the seasoned fillets in a single layer in the prepared baking dish.
04 - In a small mixing bowl, combine melted butter, fresh lemon juice, lemon zest, minced garlic, chopped parsley, and paprika if desired.
05 - Pour the lemon butter mixture evenly over the fish fillets.
06 - Place one lemon slice on top of each fillet.
07 - Bake in the preheated oven for 15 to 20 minutes, until the fish is opaque throughout and flakes easily with a fork.
08 - Remove from oven, garnish with additional chopped parsley, and serve immediately.