Balsamic-Mustard Gravy for a Roast

1/2 cup mustard
1/2 cup balsamic vinegar
1/4 cup honey
salt and pepper to taste
3 tbsp. flour

Combine vinegar, mustard, honey and salt and pepper in a sauce pan.
Bring to a simmer.

sift flour into sauce, slowly, while whisking. This may take two people (it does when I do it)
If you have any pan drippings handy, you could add them at this point, or not.

Bring the sauce back to a simmer.
Pour the sauce through a sieve to strain out the solid bits, and serve with any kind of roast meat. I prefer my Peppercorn Pork Loin, but that's just me.

NOTE: My wife, Chrissy, has a unique way of adding flour to sauces: she combines the flour with some water (usually the same amount of water, so its a roughly a 50/50 mix of flour to water). She whisks them together, and then pours the flour mixture through a sieve into the sauce, so only the flour water goes into the pan. I like her way, because with the traditional way, if you add the flour too fast, it clumps up in the sauce pan. Or at least it does when I do it.