Cook the pasta: Bring a large pot of salted water to a boil. Add the fettuccine and cook according to the package instructions until al dente. Before draining, reserve about 1/2 cup of the pasta water, then drain the pasta and set it aside. Lightly toss with a small drizzle of olive oil to prevent sticking.

Cook the shrimp: In a large skillet over medium heat, add the olive oil and butter. Once the butter is melted and slightly foamy, add the shrimp in a single layer. Season with a pinch of salt and pepper. Cook for 1–2 minutes per side, or until the shrimp turn pink and opaque. Avoid overcooking to keep them tender. Remove the shrimp from the skillet and set aside.

Prepare the Alfredo sauce: In the same skillet, reduce the heat to medium-low and add the minced garlic. Sauté for about 30 seconds until fragrant, being careful not to burn it. Pour in the heavy cream and stir gently, allowing it to warm through for 2–3 minutes. Slowly whisk in the grated Parmesan cheese, continuing to stir until the sauce becomes smooth and slightly thickened. Add Italian seasoning, red pepper flakes (if using), salt, and black pepper to taste.

Combine pasta and shrimp: Add the cooked fettuccine directly into the sauce, tossing gently to coat all the pasta evenly. If the sauce is too thick, gradually add a little of the reserved pasta water until the desired consistency is reached. Return the cooked shrimp to the skillet and gently fold them into the pasta, allowing everything to heat through for another 1–2 minutes.

Serve: Remove from heat and transfer the Shrimp Alfredo Pasta to serving plates. Garnish with freshly chopped parsley and additional grated Parmesan cheese if desired. Serve immediately while warm and creamy for the best texture and flavor.