After I roast a piece of meat, I will deglaze the pan with some wine and then add unsalted stock and some herbs. Then I reduce it by atleast 50%. Au Jus is all about the pan drippings & fond and a good hearty stock.
I'm not quite sure that you will find something as good. Quizno's sauce is probably designed in a lab. The body of good Au Jus comes from the gelatin in the stock and sometimes the sugars in the wine/aromatics. You can cheat by using a corn-starch slurry, but it won't have the same "Unxiousness" as Alton Brown says.
A cheat would be to simply roast some onions, deglaze with wine, and then add a bunch of stock along with some herbs (like thyme). Reduce this until it reaches a flavor and consistency you like. Commercial stocks use very little bones/joints because they cost lots of money relative to salt. This would get you 75% of the goodness, but you would still need an unsalted homemade stock on hand (perhaps the freezer?). You could also make a large batch of au jus ahead and freeze it in 1/2-C containers. Then simply pull them one out and nuke it for a minute or two.
Nick ~ "Egg whites are good for a lot of things; lemon meringue pie, angel food cake, and clogging up radiators." - MacGyver