Cook the pasta in a large pot of salted water per the instructions on the box, until al dente.
In a medium microwave safe bowl, heat the half & half for 1 minute to warm slightly.
Add the cream cheese stirring to soften.
Add 1/2 cup of grated parmesan cheese to the warm half & half and season with salt and black pepper to taste. [The cream cheese will melt completely when it's combined with the hot pasta.]
Drain the pasta then pour back into the pot and return to the stove top.
Over low heat, add the cream sauce, chopped chicken, pesto, and sundried tomatoes to the hot pasta. Stir continually until the cream cheese has completely melted and the ingredients are heated through and evenly coated with the sauce.
Just before serving, add the fresh spinach and lemon zest and stir until the spinach begins to wilt.
Serve immediately garnished with Parmesan cheese shavings, if desired.
Sundried tomatoes are usually packed in oil. By soaking the tomatoes, it will serve not only to soften them but, it will also remove most of the oil. If large roughly chop to bite-size.