Start by bringing a large pot of salted water to a boil. Add the fettuccine and cook according to package instructions until al dente. Reserve about half a cup of the pasta cooking water, then drain the pasta and set it aside.
In a mixing bowl, combine the raw shrimp, salt, and black pepper. Toss to coat the shrimp evenly. Sprinkle the flour over the shrimp and toss again until the shrimp are lightly coated.
Heat the olive oil and butter in a large skillet over medium heat. Once the butter has melted and the oil is hot, add the coated shrimp to the skillet in a single layer. Cook until the shrimp are golden brown and crispy, about 2-3 minutes on each side. Once cooked, transfer the shrimp to a plate and set aside.
In the same skillet, pour in the low-sodium chicken broth and bring it to a simmer. Add the whipping cream and Cajun seasoning, stirring to combine. Let the sauce simmer for about 5 minutes, allowing it to thicken slightly.
Add the cooked fettuccine to the skillet with the sauce, tossing to coat the pasta evenly. If the sauce is too thick, add a splash of reserved pasta water to reach your desired consistency. Finally, gently fold in the crispy shrimp. Serve immediately, garnished with fresh herbs or additional seasoning if desired.
