Preheat the oven to 500 degrees. Coat a baking dish with cooking spray.
Whisk the mayonnaise, 1 tablespoon of parmesan cheese, and minced garlic together until well combined.
Place the halibut pieces in the baking dish skin side down then season with sea salt and freshly cracked pepper, to taste.
Brush the mayonnaise mixture evenly over each piece of halibut on the top and sides.
Sprinkle the remaining bit of parmesan evenly on each piece of fish.
Place into the oven and bake for 10 minutes.
Turn the oven to broil and cook, watching carefully for another 1-2 minutes, or until the top is golden brown and the fish is cooked through.
Remove from the oven and sprinkle with fresh parsley.
Serve with lemon wedges. Enjoy.