Sprinkle ½ tsp of salt and ½ tsp pepper on both sides of the chicken breasts to season.
In a large skillet, heat 1 tablespoon of olive oil over medium-high heat. Add the chicken to the skillet and cook for 5 - 7 minutes on each side, until cooked through. Remove from the pan.
Lower the heat to medium-low heat, and add the butter to the skillet. Once the butter has melted, saute the garlic 2 - 3 minutes.
Stir in the spinach and tomatoes until the spinach is mostly wilted.
Sir the half and half, 1 teaspoon salt, 1 teaspoon pepper, and Italian seasoning into the skillet. Bring to a simmer.
Stir in the parsley and Parmesan cheese. Stir frequently over medium high heat until the sauce begins to thicken (aproximately 5 minutes).
Add the chicken back into the pan and spoon the sauce over it until covered.