Preparation / Directions:
Thoroughly combine the seasoning mix ingredients in a small bowl and set aside. In a separate bowl combine the onions, celery, and bell peppers. In a large skillet (preferably cast iron), heat the oil over high heat until it begins to smoke, about 4 minutes. With a long handled whisk, gradually mix in the flour , stirring until smooth. Continue cooking, whisking constantly, until roux is dark brown, about 3-5 minutes.
Remove from heat and immediately stir in the vegetables and 1 T of the seasoning mix with a wooden spoon; continue stirring until cooled, about 5 minutes. In a 2-qt. saucepan bring 2 cups of the stock to a boil over high heat. Gradually add the roux and whisk until thoroughly dissolved. Reduce heat to low and cook until flour taste is gone, about 2 minutes, whisking almost constantly. Remove from heat and set aside.
In a 4-qt. saucepan melt 1 stick of butter over medium heat. Stir in shrimp and the green onions; sauté 1 minute, stirring almost constantly. Add the remaining stick of butter, the stock mixture and the remaining 1 cup stock; cook until butter melts and is mixed into the sauce, about 4-6 minutes, constantly shaking the pan in a back and forth motion.
Add the remaining seasoning mix, stir well and remove from heat ( if sauce starts to separate, add about 2 T more of stick or water and shake pan until it combines) .