Thaw the shrimp according to package directions.
Bring a large pot of water to a boil.
Once boiling, add 2 teaspoons of salt.
Add the fettuccine and cook until al-dente, 8-10 minutes. Keep 1 cup of the starchy cooking water and then drain. Do not overcook.
Put the noodles back into the pan and cover with a lid until the sauce is ready. (Add the starchy water and stir the noodles if they become sticky before adding to the pasta in the end)
While the noodles cook, melt 1 Tablespoon of butter in a medium-size skillet.
Once melted, add 1 teaspoon of garlic and cook for one minute or until fragrant.
Add the thawed shrimp to the pan. Make sure that the shrimp are in a single layer, and each is contacting the surface of the skillet.
Sprinkle a ½ teaspoon of salt over the shrimp and lightly dust with pepper.
Cook each side for 2-3 minutes, or until they are slightly golden brown. (They are already cooked, so you don’t need to worry about undercooking.)
Once cooked, remove heat and set aside.
In a large skillet, add 2 Tablespoons of butter and melt.
Once melted, add 2 Tablespoons of minced garlic and cook for one minute or until fragrant.
Sprinkle the flour onto the garlic and stir together for another minute.
Slowly add the chicken broth to the skillet and use a whisk to blend the mixture. Continue whisking until the sauce is smooth. You can use a spatula to try and eliminate larger lumps.
Allow to simmer for a minute or until it starts to thicken.
Add the parmesan cheese, salt and pepper and whisk until melted.
Taste to see if additional salt or pepper is needed.
Remove ½ of the sauce and set aside. (You may not need all of it.)
Add the pasta and shrimp to the skillet and toss together using a pair of tongs.
Serve immediately and garnish with freshly chopped parsley and cracked pepper.