Pour slowly into the skillet and keep stirring. Now, you do not need to use the whole Roux, if the sauce is thick enough, discard Roux if you have any left.
Garnish it with dry parsley and serve immediately.
You can use any peppers, sweet or spice and of course any color that you desire. However, if you use regular sized peppers than you will need to slice them at least in quarters and take the seeds out, and more time until they can get softer.
You do NOT have to use any Crushed red pepper or anything spicy if you cannot handle or don't like spicy food. It is optional, and you are in control how much is too much.
If you don't have half and half or heavy whipped cream just use milk. It works fine with milk because when you are using roux it will become creamy.