Slice the mushrooms, either into half slices, or quarter slices if larger. They should all be relatively similar in size, easily bite-size. Set aside.
Add the Marsala or Madeira, along with the beef stock and stir through the vegetables and roux. Add the beef bouillon and stir through to melt into the sauce.
Cook till thickened, about five to eight minutes. At this point drizzle 1 tsp of aged thick balsamic vinegar into the sauce and stir it through. Taste and see if you would like to add more vinegar.
If you can find fast fry pork loin chops, these will be easy to pound down into the desired thickness. If they are on the smaller side, just arrange for two chops per person.
If you don't have beef bouillon cubes or paste, use a few hearty dashes of Worcestershire sauce, soy sauce or even Maggi.
You want to use aged balsamic vinegar in this instance. The older and more syrupy the better. You only need 1 tsp or so, but you will see how it adds a perfect sweetness as well as a tang to cut through the richness of the sauce.