Season chicken breasts with salt, pepper, and Italian seasoning. Heat olive oil and butter in a skillet over medium-high heat. Cook chicken until golden brown and the inside reaches 165°F. Remove and rest before slicing.

Bring a large pot of salted water to a boil. Cook fettuccine until al dente according to package directions. Save ½ cup pasta water, then drain.

In the same skillet, add butter, heavy cream, and garlic. Cook over medium-low heat while whisking until smooth.

Stir in freshly grated Parmesan cheese. Keep mixing until the sauce becomes creamy and thick.

Add cooked fettuccine to the Alfredo sauce. Toss until coated. Add pasta water if needed to loosen the sauce.

Slice chicken and place it over the pasta. Top with parsley and extra Parmesan cheese.