It could be a pan sauce or not. If a pan sauce, if you deglaze with stock and some wine, maybe some added aromatics, and reduce quite a bit, and then thicken at the end with something that gives both good texture and good flavor release. I use a mix of 1:10 xanthan gum and arrowroot starch. You can make a slurry with this and whisk it in. Roughly a half teaspoon per cup of sauce. The starch needs to be heated to hydrate, but it only take a minute. This gives a creamy mouthfeel that doesn't mute flavors the way cream or butter would.
For more constructed sauces, I make a coulis (basically an intense, thickened stock ... similar to classical demiglace, but better tasting). This used to be a big deal to make; now that the pressure cooker has come along to save the day, I just make a pressure cooker stock with a high ratio of solids to water. I thicken it with 0.3% lambda carrageenan and 0.1% xanthan gum (plus all the natural gelatin). This mix is a little trickier to use, since it has to be blended in to disperse, which makes an annoyingly stable foam. And it needs to be added after you've defatted the stock. So I make and strain the stock on one day, chill it overnight to let the fat separate, skim it off, and then blend in the gums.
Then I put it on the stove again to simmer it lightly (you can use this opportunity to put in some additional parsley and other herbs) to let the air com out. Then you can chill it and portion it for the freezer, etc..
This can be used as the base for any kind of quick sauce ... use it to deglaze a pan, add reduced mushrooms and mushroom liquid, or reduced wine or fortified wines, etc. etc..
