quick sauces....

[melia]

Following Manton's exellent piece on faux demi-glace i thought it might be a good follow up for people to tell what fantastic sauces we can turn it into...i know there are plenty of books on the subject, but i'm talking more of great sauces we can whip up at the last minute to pep up an otherwise regular midweek meal
There seems some talented culinary minds here, so how about sharing with some of us enthusiastic beginners...[/b]