There are several ways to thicken a sauce, each with its own characteristics. On method, which I have to admit, I under-utilize is to use cornstarch and a little water. Using cornstarch is nice, because unlike say a roux, or other flour based thickeners, you don’t really need to cook out the raw taste of the flour for several minutes – with cornstarch you’re ready to go right away. I'll sometimes use butter, but that method can cause you to break the sauce....which is a mess. Corn starch gives the sauce a glossy look, and mouth feel, which is also very cool. Finally, using cornstarch to thicken a sauce is supper quick and easy. At the last minute, if you find you need it, you can just grab a bit of cornstarch, mix with water, and you’re good to go. Hope you find the technique useful!!