While the mushrooms are cooking heat the other teaspoon of oil in a medium skillet over medium heat. Add the minced shallots and cook gently stirring frequently until they are soft and translucent. Add the cranberries, port, chicken stock, salt, pepper and maple syrup.

Increase the heat slightly and cook until all but about 1 tablespoon of the liquid has evaporated. Remove from the heat and set aside to cool.

When the mushrooms are done fold them into the cranberry mixture. Add the rosemary and toss until well blended. Refrigerate at least 30 minutes.

Preheat the oven to 400°F.

While the stuffing is cooling trim the pork tenderloin of all excess fat. Stuff the pork loin using about 3/4 of the cranberry/shiitaki mixture.

Place a large non-stick skillet in the oven to heat. After about ten minutes lightly spray with olive oil and add the pork loin to sear. This will require turning about every 4 minutes for the first 15 so as to sear the outside well.

While the pork is roasting place the remaining cranberry/shiitaki mixture in a non-reactive sauce pan with the tawny port and 1/4 cup chicken stock over medium heat. When the sauce is simmering reduce the heat to medium-low. As the sauce reduces ad the water about 2 tablespoons at a time.

While the sauce is cooking place the 2 teaspoons of cornstarch in the remaining 1/4 cup chicken stock and stir well until blended. Set aside.

The roast will take about 45 minutes to cook to an internal temperature of 160°F. Remove to a cutting board to rest for about 3 - 5 minutes.

While the meat is resting increase the heat under the sauce to medium and add the cornstarch/chicken stock mixture. Stir well to blend and thicken the sauce.

Cut the pork loin into 6 slices of equal thickness. These will be about 1 - 1 1/2 inches thick. Remove the trussing twine as you slice.

Serve over Mashed Potatoes with the thickened sauce.