Bring a large pot of salted water to a boil. Cook the fettuccine according to the package instructions until al dente. Drain, reserving ½ cup of pasta water, and set aside.

While the pasta cooks, heat 1 tablespoon of butter and 1 tablespoon of olive oil in a large skillet over medium heat. Add the shrimp in a single layer and season with salt and pepper. Cook for 2-3 minutes per side, or until the shrimp are pink and opaque. Remove shrimp from the skillet and set aside.

In the same skillet, add the remaining butter and olive oil. Sauté the minced garlic for about 30 seconds, until fragrant. Add the heavy cream, chicken broth, Parmesan cheese, Italian seasoning, and crushed red pepper flakes (if using). Stir well to combine and let the sauce simmer for 3-4 minutes, until it thickens slightly.

Add the cooked pasta and shrimp back into the skillet with the sauce. Toss to coat the pasta and shrimp evenly in the sauce. If the sauce is too thick, add a splash of the reserved pasta water until the desired consistency is reached. Season with additional salt and pepper if needed.

Serve immediately, garnished with fresh parsley and a squeeze of lemon juice. Pair with your favorite garlic bread for a complete meal.