The good folks at Ogilvy and Harrah's arranged a trip to the New Orleans School of Cooking for the blogger group as part of "The Greatest Weekend Ever". Which, unbeknown to me, was part lesson, part theatre, and yet another meal. If you have a chance to visit New Orleans, this is a fun and relatively inexpensive way of spending a couple of hours - and you'll walk away full.
The key element in the lesson, where two main dishes are prepared (a soup, and crawfish etouffee), is the importance of roux is to the New Orleans (and Louisiana) cooking. Story is that since poor people couldn't afford spices, the browning of flour in oil, by way of the Maillard reaction, produced a range of flavors that anyone could attain in a short period of time. Roux comes in a variety of colors, ranging from blond to nearly black, at each level decreasing in thickening power, but increasing in flavor complexity. Add the variety of oils used in roux making (our instructor was particularly enamored of lard, although created a roux from butter as well), and there's a range of flavoring components available for the dishes known well in this region: gumbo, etouffee, and other stews.