Step 1: Prep pan
I used fresh ground black pepper and some cajun seasoning.
Step 2: Prep and add fish
Holding the fish over the sink, lightly rub it down with a thin layer of cornstarch. Give your fish a gentle shake to remove any excess cornstarch; this is intended to be an extremely thin layer. The cornstarch will help seal moisture into your fish, and help form a slightly crispy exterior.
Drop it skin-side down in the pan and cook over medium-high heat.
Step 3: Spray and season
Add the same spices that you originally added to the pan. I added black pepper and cajun seasoning, trying to get roughly the same ratio as I dd in the pan.
Step 4: Flip
After flipping watch until it has cooked slightly less than 1/3 of the way from the other side. The center will continue to cook after you remove the fish from the hot pan; if you wait until there's no pink left in the center the fish will overcook on the plate. Fish are delicate.
If you like, press the thick end up against the side of the pan to sear it before removing the fish.