01 - Preheat oven to 400°F. Lightly grease a baking dish large enough to fit fillets in a single layer.
02 - In a small bowl, mix olive oil, minced garlic, lemon zest, lemon juice, thyme, parsley, sea salt, and black pepper.
03 - Pat halibut fillets dry with paper towels and place them evenly in the baking dish.
04 - Brush the marinade evenly over each fillet, coating thoroughly.
05 - Top each fillet with thin lemon slices.
06 - Bake in the preheated oven for 15 to 18 minutes until the fish flakes easily and is opaque throughout.
07 - Sprinkle additional chopped parsley over fillets and serve immediately.