Cook linguini as directed, drain, keep warm. In bowl, combine 3/4 cup broth, 1/3 cup broth, lemon juice, red pepper and salt.
In lg skillet, heat oil over medium heat. Add shrimp, pine nuts and garlic. Cook until shrimp are pink. Remove shrimp from pan. Add mushrooms and butter to pan. Cook 3 mins.
Add broth mix to pan. Bring to a boil. Reduce heat and gently boil, uncovered for 5 min. return shrimp to pan. Heat through. Add shrimp mix and spinach to pasta, toss to combine. transfer to lg serving bowl and sprinkle w/ asiago cheese.