01 - Set the oven to 400°F and lightly grease a baking dish large enough to hold the fillets in a single layer.
02 - Pat haddock fillets dry with paper towels and place them evenly in the prepared dish.
03 - In a small bowl, whisk together olive oil, lemon juice, lemon zest, minced garlic, sea salt, and black pepper until combined.
04 - Evenly drizzle the olive oil mixture over the fillets.
05 - Sprinkle drained capers and chopped fresh parsley over the fish.
06 - Bake in the preheated oven for 16 to 18 minutes, until the fish flakes easily and is opaque throughout.
07 - Present hot, garnished with additional parsley and lemon slices as desired.