Here's a very quick sauce that's easy to make and delicious. It involves no roux or corn starch or cheese. It was originally devised as a sauce for Chicken Cordon Bleu when a lazy cook (me) had no desire to make a cheese sauce or a Hollandaise.
I'm sure someone has thought of this one before, and given it a name or two, but I'm unaware of what it's called. It sure tastes like the sauce Chili's used to put on their Caliente Catfish.

Ingredients:
1/2 cup heavy cream
2 tsp chili sauce
1/2 tsp Dijon Mustard
1/4 tsp onion powder
1/4 tsp garlic powder
1/4 tsp black pepper

Reduce sauce over medium heat, stirring constantly. Serve over chicken, asparagus, stuffed flounder, or something out of your own derision.