Prepare linguine according to package directions. In large skillet over medium-high heat cook shrimp, mushrooms and garlic in butter 5 minutes until shrimp turn opaque, stirring frequently. Remove mushrooms, and shrimp from pan and add enough cream to make a sauce. Add Parmesan to taste. Cook, stirring constantly to deglaze. Thicken with cornstarch as desired and add salt and pepper to taste. Drain linguine. In large serving bowl combine shrimp mixture, linguine, and sauce. Toss gently to coat well. Top with remaining 3 Tbs. cheese Garnish.