Place pasta in a pot of boiling water. Add 1 tsp salt and stir. Boil 11-13 minutes.
While the pasta is boiling, place frozen shrimp in a saute pan and cook according to package instructions.
Drain and rinse pasta when finished cooking and set aside. Remove shrimp from saute pan and set aside.
Add flour, milk, heavy cream, and cheese directly to the melted butter in the saute pan. Stir together and heat till simmering. Add salt and pepper, to taste.
Place pasta on plates and top with hot alfredo sauce. Top with hot shrimp.