SHRIMP AND CRABMEAT ETOUFFEE Recipe

Several weeks ago, after enjoying a great etouffee at a cooking demonstration and tasting from a local top-rated chef, I was inspired to make my own version the following day. Since Mardi Gras was coming up the following week, and since I am a seafood lover, I wanted to make a version with seafood, or more likely shellfish. So, I pulled out one of my cookbooks from Chef John Besh, "My New Orleans, the Cookbook," to use as a guide. His recipe was for crabmeat and frog, but I substituted the frog with shrimps (not that I don't eat frog, but my local market doesn't stock the product -- need to get that at Lobster Place in NYC). For the roux, I prefer to use arrowroot in lieu of flour. Guess, it's not authentic New Orleans, then??