1. Cut pork diagonally into thin slices. Sprinkle pork with salt and pepper; rub with garlic. Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray; add oil. Add pork; cook 1 to 2 minutes on each side or until done. Transfer pork to a platter; keep warm.
2. Recoat skillet with cooking spray. Add mushrooms and shallots; cook, stirring often, 5 minutes.
3. While mushroom mixture cooks, place cornstarch in a small bowl. Gradually add stock and sherry, stirring with a whisk until smooth. Stir stock mixture into mushroom mixture, scraping to loosen browned bits. Bring to a boil; cook, stirring constantly with a whisk, 1 minute or until thickened. Return pork and accumulated juices to pan; cook 1 to 2 minutes or until thoroughly heated.
Serve with: Balsamic-Glazed Green Beans