(I know, I know, what if you don't just happen to have brown sauce in the
fridge or freezer! As much as I LOVE Gourmet (and believe me, I do) that's
my primary complaint about some of their older recipes. So, what do you do
here? Omit the brown sauce, make brown sauce, or buy demi-glace? If you
decide to make some brown sauce, please see below*)

Season the pork with salt and pepper and rub it all over with the mustard.
On a sheet of wax paper sprinkle the brown sugar and roll the pork in it, coating it well. In a roasting pan heat the butter and the oil over moderately high heat until the fat is hot and in the fat brown the pork. Remove the pan from the heat, add the bourbon, heated, and ignite it. Shake the pan until
the flames go out, add the wine, sage, thyme, bay leaf, and salt and pepper
to taste, and bring the mixture to a boil. Roast the pork, covered, in a preheated 425-degree F. oven for 30 minutes more. Transfer the pork
to a platter and keep it warm, covered loosely.
Skim the fat from the juices, add the brown sauce, and heat the mixture
over moderately low heat, stirring, and adding water if necessary to
achieve desired consistency. Discard the strings the roast and slice
the pork thin. Spoon some of the sauce over the pork and serve the
remaining sauce separately.
 

* from Julia Child's
The Way to Cook
October 1993, Alfred A. Knopf