1. Preheat oven to 375°.
2. Place pizza crust on a baking sheet coated with cooking spray. Bake at 375° for 5 minutes. Remove crust from oven (do not turn oven off); set crust aside.
3. Heat a large nonstick skillet over medium-high heat. Coat pan with cooking spray; add 1 teaspoon oil to pan, swirling to coat. Add mushrooms to pan; sauté 8 minutes or until moisture evaporates. Stir in thyme; spoon mushroom mixture into a bowl.
4. Add remaining 1/2 teaspoon oil to pan, and reduce heat to medium. Add garlic to pan; cook 45 seconds. Combine milk and flour in a small bowl, stirring well with a whisk. Add milk mixture to pan; cook 2 minutes or until thick, stirring constantly. Add Asiago and pepper, stirring until cheese melts.
5. Spread sauce over crust, leaving a 1/2-inch border. Top evenly with mushroom mixture, tomato slices, and mozzarella. Bake at 375° for 10 minutes or until cheese melts and begins to brown. Cut pizza into 8 wedges.