Bring a large pot of water to a boil and add 1 tsp salt.

Cook the fettuccine until al dente, then reserve 1 cup pasta water and drain.

Heat 1 tbsp butter in a large skillet over medium high heat.

Add the chicken and cook until browned and cooked through, 6 minutes, stirring occasionally; season with 1/2 tsp salt and 1/2 tsp pepper near the end.

Transfer the chicken to a plate and reduce heat to medium low.

Add the remaining 1 tbsp butter to the skillet, then add the garlic and Italian seasoning and cook for 30 seconds.

Pour in the heavy cream and bring to a gentle simmer for 3 minutes, stirring.

Remove from direct high heat and whisk in the Parmesan a handful at a time until smooth.

Return the chicken to the skillet, add the cooked fettuccine, and toss to coat.

Add reserved pasta water 2 tbsp at a time until the sauce turns glossy and clings to the noodles.

Taste and adjust salt and pepper, then serve immediately topped with parsley and more black pepper.