Sauté minced onion and garlic in hot oil in a medium saucepan over medium-high heat 4 to 5 minutes until tender; add sliced fresh mushrooms, and sauté 5 minutes.
Stir together gravy mix, beef broth, and soy sauce. Stir into mushroom mixture, stirring to loosen particles from bottom of skillet. Bring to a boil over medium-high heat, stirring constantly. Reduce heat to medium, and cook, stirring occasionally, 4 to 5 minutes or until slightly thickened. Stir in pepper.