Scrub and wash potatoes. (Do not peel).
Cut potato into a barrel shape and slice paper-thin pieces, all of the same size.
Season rockfish with salt & pepper on both sides. Lay the potato slices over the fish layering one over the other. Repeat 10 times.
Add egg to 1/2 of the oil and lightly brush over fish.
Season with salt and pepper.
Heat pan to medium.
Sear potato on both sides until golden.
Heat in oven at 350˚ for 10 minutes.