Cook pasta as per package instructions undercooking by a few minutes, until al dente. Drain and set aside.
Meanwhile, preheat large Dutch oven or deep skillet on medium heat and swirl oil to coat. Season chicken breasts with salt and pepper, add to the pot and cook for 4-5 minutes on each side or until cooked through. Remove onto a cutting board, let rest for a bit and then thinly slice.
In a small bowl, whisk milk and flour. Add to the pot and cook until thickened, about 2 minutes. Add cream cheese and pesto, stir and cook until melted.
Now add drained cooked pasta, sliced chicken and spinach. Give a few gentle stirs until spinach has wilted.
Sprinkle with Parmesan cheese, parsley and freshly ground black pepper and serve immediately.
Notes
Store: Leftovers can be stored in the refrigerator in an airtight container up to 4 days.
Freeze: I don't recommend to freeze pasta.
Pasta: It can be white, whole wheat or gluten free pasta. Use any short pasta like bow ties, fusilli etc.