01 - Preheat the oven to 400°F. Line a baking dish with parchment paper or lightly grease it.
02 - In a small bowl, whisk together olive oil, lemon juice, lemon zest, minced garlic, thyme, salt, and black pepper.
03 - Pat the halibut fillets dry using paper towels and place them in the prepared baking dish.
04 - Brush the marinade evenly over the halibut fillets and top each fillet with a couple of lemon slices.
05 - Bake in the preheated oven for 15 to 18 minutes, or until the fish is opaque and flakes easily with a fork.
06 - Remove from oven, sprinkle with fresh parsley, and serve immediately.