Thaw one roll of phyllo, following the thawing instructions on the package. Preheat the oven to 350 degrees F.

In a medium skillet, heat 1 tablespoon butter and 1 tablespoon oil over medium heat. Add shallots and mushrooms; cook until mushrooms are tender, about 10 minutes. Remove from the heat. Stir in the parsley, salt, and pepper, then cool to room temperature.

In a small bowl, combine the garlic salt, thyme, oregano, and paprika. Rub the seasonings over all sides of the pork. Put the pork in a roasting pan and bake for 20 minutes, turning once. Remove pork from the pan and cool for 10 minutes.

In a small bowl, melt the remaining 2 tablespoons of butter with 2 tablespoons of oil. Unroll the phyllo sheets and cover them with plastic wrap, then a slightly damp towel to prevent drying out.

Layer 10 phyllo sheets, brushing each one with the butter-oil mixture and sprinkling 1 teaspoon of breadcrumbs over each one.

Spread the mushroom mixture along one short edge of phyllo, leaving a 2” border. Place pork on top of the mushroom mixture then loosely roll up from the short edge. Tuck the edges at the end.

Place the phyllo-wrapped pork seam-down on an ungreased baking sheet, brush with the butter-oil mixture, and sprinkle with seasoned breadcrumbs. Score the top into 6 sections.

Bake for 30 minutes or until golden brown. Remove from the oven and let stand for 10 minutes before serving.

Heat the mushroom gravy in a small bowl according to the package's directions. Spoon the gravy onto a plate and place the phyllo-wrapped pork tenderloin on it.