I'm usually for simply prepared fish, my go to, for white fish, is a little mayo on top before baking. But the best upclass is some pesto (homemade pesto lasts forever and tastes heavenly) You can also simply use your favorite fresh or frozen herbs.
4 White Fish Fillets, I usually use Tilapia
1/4 cup Mayo
1/4 cup Pesto
OR Herbs (optional)
Alright this sounds a little odd, and it take time and usually a meal to convince others I actually do do this, but I have been for years. To cook any sort of white fish, I smear on a little mayo mixed evenly with pesto on the fillets, top with fresh cracked pepper, and place them on an ungreased foil lined baking dish.
In a 425 oven it takes around 15 mins (it depends on the thickness of your fillets). Just test it flakes and if it does, it's done. Serve immediately with carb of choice.