There are few worse travesties than the pompano en papillote found in traditional New Orleans restaurants. It starts with the best fish there is—one I find so good that sauces tend to detract from, not add to, the flavor. Then this great fish goes into a parchment bag with the gloppiest kind of “light roux, white wine, three or four seafood” sauce.

I will admit, however, that the idea of the papillote—to keep the fish moist by cooking it essentially in its own steam in a parc