Thaw shrimp, if frozen. Peel and devein shrimp, leaving tails intact if desired. Rinse shrimp; pat dry with paper towels. In a Dutch oven cook linguine according to package directions; drain. Return linguine to hot pan; cover and keep warm.
Meanwhile, in a small bowl combine broth, sherry, lemon juice, salt, and crushed red pepper; set aside.
In a large skillet cook shrimp, 1/4 cup pine nuts, and garlic in hot oil over medium heat for 2 to 3 minutes or until shrimp are opaque, stirring frequently. Remove shrimp mixture from skillet.
Add mushrooms and butter to skillet. Cook about 3 minutes or until mushrooms are nearly tender, stirring occasionally. Carefully add broth mixture. Bring to boiling; reduce heat. Boil gently, uncovered, for 5 minutes. Return shrimp mixture to skillet; heat through.
To serve, divide warm linguine among shallow bowls. Top with shrimp mixture, spinach, cheese, and, if desired, additional pine nuts.