Preheat the oven to 400°F.

In an 8-by-12-inch baking dish, season the pieces of fish with salt, pepper, garlic powder, and red pepper flakes.

Top with 1 tablespoon of butter on each piece of fish.

Bake for 15 minutes, or until the fish is white and opaque throughout.

Remove from the oven, and pour the lemon juice over the fish.

Serve with a wedge of lemon and a sprinkle of parsley.