In a large pot, bring salted water to a boil. Add fettuccine pasta and cook according to package instructions until al dente. Drain and set aside, reserving 1/2 cup of pasta water.
In a medium bowl, toss the shrimp with Cajun seasoning until well coated.
In a large skillet over medium-high heat, heat 2 tablespoons of olive oil. Add seasoned shrimp and sauté for about 2-3 minutes per side, or until they turn pink and opaque. Remove shrimp from the skillet and set aside.
In the same skillet, add the remaining tablespoon of olive oil and minced garlic. Sauté for 30 seconds until fragrant. Pour in the chicken broth and heavy cream, stirring well to combine. Bring the mixture to a simmer.
Gradually whisk in the Parmesan cheese, allowing it to melt and create a smooth sauce. If the sauce is too thick, add some reserved pasta water until desired consistency is reached.
Add the cooked fettuccine and sautéed shrimp to the sauce, tossing everything together until well coated. Season with salt and pepper to taste.
Remove from heat and let it sit for a minute to thicken slightly.
Notes
Serve in shallow bowls, garnished with chopped parsley and extra Parmesan.