Place fillets in a glass baking dish.
Mix paprika, onion powder, salt & pepper in a small bowl and sprinkle on both sides of the fish. Pour 1/2 cup of water over the fish so they are half-submerged. Cover and set aside.
Preheat the oven to 350 degrees F (175 degrees C).
Melt butter in a small saucepan over medium heat until frothy. Add water, using a whisk to remove any browned bits. Whisk in more butter if the sauce is too thin. Bring to a boil and let boil for 1 minute.
Place the baking dish with fish in the oven, pour the butter mixture over the fish and bake for 7–9 minutes (depending on the thickness of fish) or until flesh flakes easily. (With thin pieces of fish, 7 minutes will cook it thoroughly; thicker pieces of fish should cook longer.)
Serve and enjoy!
Serving Suggestions: This dish is great over a bed of steamed asparagus. It’s especially good with the butter sauce.