I used Isaac Topus gumbo recipe in the last (YouTube it) and always stirred roux for 45 minutes or more. I was afraid of high heat and burning it. This time I used the Americas Test Kitchen dry roux method, came out excellent. Cup of all purpose flour in a stainless steel skillet, 425f oven for about 45 minutes, stirring often. My days of stirring roux for 45 minutes are over.