In a pot or Dutch oven, cook pasta al dente according to package instructions. Drain the water and add back to the pot to keep warm.
Cut chicken breast in half lengthwise. Combine italian seasoning, salt and pepper, and season chicken on all sides.
Add oil to a large skillet. Once hot, add chicken and cook over medium-high heat until the chicken reaches an internal temp of 165°F. Remove the chicken from the skillet, slice or cube it, and cover it to keep warm.
Add the butter, garlic, and sun-dried tomatoes in the same skillet and cook for 1 minute. With a wooden spoon, scrape off the browned bits at the bottom of the pan.
Stir in the heavy cream, milk, parmesan cheese, italian seasoning, salt, and pepper. Turn the heat to low and cook until the sauce starts to thicken.
Add the spinach, cubed chicken, and pasta into the sauce and cook until the spinach is wilted and the chicken is reheated, about 1 minute.
Serve and enjoy.