01 - Preheat oven to 400°F. Line a baking dish with parchment paper or lightly grease with olive oil.
02 - Pat halibut fillets dry with paper towels. Brush both sides with olive oil, then season with sea salt and black pepper.
03 - Place fillets in the prepared baking dish, spacing them apart evenly.
04 - Melt butter in a small saucepan over medium heat. Add minced garlic and cook for 1 minute until fragrant without browning.
05 - Stir in lemon zest and lemon juice, then remove saucepan from heat. Incorporate chopped parsley and dill if using.
06 - Spoon about half of the lemon butter sauce over the halibut fillets evenly.
07 - Bake for 15 to 18 minutes, until the fish flakes easily with a fork and is opaque throughout.
08 - Remove from oven, drizzle with remaining lemon butter sauce, and garnish with lemon slices and extra parsley before serving.