Deglazing a pan after sauté
ing foods can provide the basis of a very flavorful sauce. Once you have transferred the cooked food and before the pan has a chance to cool down, add a little water or wine, swirl it, and deglaze
using a spatula to work in small morsels that may have adhered to the bottom. Then add seasonings and salt to taste.
If you want to thicken the sauce, you could use cornstarch or flour, but arrowroot or tapioca starch will give a nice luster to vegetables. But whatever you do, don’t add any of these dry powders to an already hot liquid or they will lump.
The best way that I've found to go about it is to put a few tablespoons of powder into a cup and dissolve it in a little cold water. Then raise the temperature of the sauce, add the liquid thickener a little at a time and stir continuously as it begins to thicken, preferably with a wire whisk. Make sure you bring it up to a boil or it will have a grainy or powdery texture. If it is too thick, add water; too thin, add more thickener.
I much prefer this method of making a sauce over using a roux because it is lighter and just as flavourful.