Bring a large pot of salted water to a boil. Add 8 oz of fettuccine pasta and cook according to package instructions until al dente, about 10 to 12 minutes. Reserve a cup of pasta water, then drain and set pasta aside.
Pat 2 boneless, skinless chicken breasts dry and season both sides with salt, pepper, and 1 teaspoon Italian seasoning. Heat 1 tablespoon olive oil in a large skillet over medium-high heat. Cook chicken 5 to 7 minutes per side until golden and cooked through. Remove and let rest, then slice.
Reduce skillet heat to medium and add minced garlic. Sauté for 30 seconds to 1 minute until fragrant, being careful not to burn.
Pour in 1 cup heavy cream and stir, scraping up browned bits. Bring cream to a gentle simmer.
Gradually whisk in 1 cup grated Parmesan cheese until smooth and melted. Sauce will thicken. Taste and adjust salt and pepper. Add reserved pasta water if sauce is too thick.
Add cooked fettuccine and sliced chicken to skillet. Toss gently to coat pasta evenly with sauce. Heat for 1-2 minutes until warmed through.
Garnish with freshly chopped parsley and serve immediately. Pair with green salad or crusty bread if desired.