Preheat your oven to 375°F (190°C).
Line a baking dish with parchment paper or lightly grease it with ghee.
Place haddock fillets in the dish. Drizzle with lemon juice and sprinkle with sea salt and pepper.
Bake for 12–15 minutes, or until the fish flakes easily with a fork.
While the fish is baking, melt the ghee in a small saucepan over low heat. Add garlic (if using) and sauté gently until fragrant—about 30 seconds. Remove from heat and stir in the chopped parsley.
Once the fish is done, plate the fillets and spoon the warm parsley ghee over the top. Garnish as desired and serve immediately.