Begin by cooking the fettuccine pasta according to package instructions in a large pot of salted boiling water. Once cooked to al dente, drain and set aside.
While the pasta is cooking, season the chicken breasts with salt, pepper, and Italian seasoning on both sides.
In a large skillet over medium heat, heat the olive oil. Add the seasoned chicken breast and cook for about 6-7 minutes per side, or until the chicken is golden brown and cooked through. Remove from the skillet and let it rest for a few minutes, then slice into strips.
In the same skillet, add the minced garlic and sauté for about 30 seconds until fragrant, being careful not to burn it.
Pour in the heavy cream and stir, allowing it to come to a gentle simmer. Cook for about 2-3 minutes until it starts to thicken slightly.
Lower the heat and gradually whisk in the grated Parmesan cheese until melted and smooth. Add the fresh spinach and continue stirring until wilted.
Combine the cooked fettuccine and sliced chicken into the creamy sauce, tossing everything together until well coated. Adjust seasoning with salt and pepper to taste.
Serve immediately, garnished with fresh parsley on top.