Being from Louisiana, going low carb was difficult. So many recipes start with, ahem, ROUX! I've found a wonderful, tasty solution with 0 net carbs. That's right, 0 net carbs. I've been using it for about 6 months and it hasn't failed me. Even my non-low carb friends didn't notice a difference in my gumbo or sausage and gravy recipes.
What is the secret ingredient? Xanthan gum! Xanthan gum has 7g of carbohydrates per serving and 7g of fiber per serving for a 0 net carb total. The biggest trick to using Xanthan gum as opposed to flour is to remember that you use FAR less Xanthan gum than you would flour. I use one tablespoon of Xanthan gum for recipes calling for 1/2cup - 1 cup of flour. So, for gumbo, I heat 3/4 cup oil and then add one tablespoon of Xanthan gum. I brown it to the desired color and make my gumbo as I would with regular, flour based roux. I also use this ratio for my sausage and gravy recipe.
For recipes using a butter roux (etoufee, etc) use one to two teaspoons per stick of butter, depending on the amount of liquid you will be adding. The first roux I made with Xanthan gum, I substituted the same amount of Xanthan gum for the flour in the recipe, and I couldn't add enough liquid! The Xathan gum roux just soaked it up. I had so much roux after that, that I cooked with it for a week and ended up throwing away what was left. Melt your butter, add the teaspoon of xanthan gum and darken to desired color. I usually go with a peanut butter color for my etoufee.
Last tip: Xanthan gum darkens faster than flour, so be sure to stir constantly! It does seem to burn a bit faster, too, so have your other ingredients ready to add or space on the stove to push it aside.
Happy Cajun Cooking!