PCook the fettuccine pasta according to the package instructions. Before draining, reserve ½ cup of pasta water.
Heat oil in a skillet, brown mushrooms, and add garlic.
Make space, and cook shrimp with seasoning.
Melt butter, simmer with pasta water, cream, and seasonings, and add Parmesan.
Add the cooked fettuccine pasta to the skillet with the shrimp and mushrooms. Pour the creamy sauce over the mixture and toss to coat everything evenly.
Squeeze juice from two lemons into the skillet and stir to combine.
Serve the dish immediately, garnished with chopped scallions and additional Parmesan cheese if desired.