Roux RouxIn a deep pot, add 1/2 cup of vegetable oil and heat on high. Add equal amount of all purpose flour. Continue to watch roux until brown and sort of pasty, sort of dry and sort of clumpy. This is a critical part. If you burn it, throw it away and start over. It's better to make the correct amount of flour and oil mixture in the beginning rather than trying to add more roux later.
Add 1 chopped onionAdd 1 cup of water. Stir until well blended. This is another critical point. Add too much water too fast and you will need to add more roux mixture. Keep adding cups of water until the sauce has less than a watery feel. If you need to add more roux, be careful to not add any roux that is burnt. Cook for another 30 minutes to an hour.
The longer the roux sits before eating the more time it has to absord all of the seasoning that you've added. A roux, just like red beans always tastes better the next day.