FoFa says:
"So always in my search for an easier way, I wanted to make a dark roux, thought i would try this method for a change. This method actually can make anywhere from a white to a dark roux depending on how long you bake the flour. The smell while raw flour is baking, is, well, not a pleasant smell, at least to our household. It is not horrible, or over powering, just don't expect baked bread smell."
Cookie Sheet
All Purpose Flour
Preheat oven to 350 or 375.
350 takes longer, 375 requires closer watching.
Spread flour on dry cookie sheet.
Bake in middle of oven.
If you want a white roux, give it 10-15 minutes.
Any other color of roux, check it every 15 or 20 minutes.
The color will be lighter here than an actual roux. The color will darken when you mix it into whatever you are using it later.
My dark roux (you could see it if the pictures worked) took about 75 minutes at 375.