Fish Pontchartrain in the French Quarter
Had to look up Pontchartrain sauce. Found a variation, as with anything cooked in N: can be a simple sauce with lump crabmeat or a complicated sauce with shrimp stock and backfin crabmeat and I am sure many things in between.
I would think that if you called K-Paul's, they might have it on the menu, or since they specialize in blackened dishes, could easily prepare it. I would not go there in jeans, but I have seen people casually dressed in there.