Fish Saute Methods

[schoenfelderp]

I've been comparing Thomas Keller's methods (from TFL) for sauteing fish. Each is very similar in its basic pattern, but there are slight variations to each, and I'm curious as to whether anyone knows why there are these variations.

Examples:
He flours the skin side of halibut, and doesn't weight it down, but with black sea bass he doesn't flour it and does weight it down.
For striped bass he doesn't flour, doesn't weight it down, and after a couple minutes he adds butter and takes it off heat covering it to steam.