Cook pasta according to package directions. Drain and return to pot. Add spinach and toss until spinach wilts. Set aside.

Meanwhile, in a large saute pan saute thawed shrimp in 1 tablespoon of butter over medium heat for about 4-5 mins until pink and cooked through. Set aside. 

In a large nonstick skilled melt 2 tablespoons of butter over medium heat. Add mushrooms and stir until cooked and reduced (about 7-8 minutes). 

Add onion to the skillet and continue to stir and cook for 10 minutes or until onion is tender. 

Stir in garlic for 30 seconds.

Add chicken broth. Increase heat to medium high. Stirring occasionally until sauce slightly thickens (about 7-8 minutes).

Stir in cream cheese, salt, pepper and nutmeg until smooth. 

Stir in the shrimp until heated through. 

Pour shrimp mixture over the pasta and spinach. Toss until mixed together. 

Sprinkled Parmesan cheese over the top. 

Serve immediately.