To make your roux, in a large cast iron skillet, mix together the flour and the canola oil. Place in an oven set at 350 degrees, walk away and let it cook for two hours. No hovering, no stirring, no nothing! After a couple of hours, take it out of the oven and it should be chocolate brown. Now, you can also do it the standing over the stove method if you prefer, but I don’t.