Preheat oven to 375.
Bring a large pot of salted water to a boil; add the manicotti and cook until the pasta is al dente. Drain and set aside.
In a small saute pan, cook the spinach in 1 T olive oil until wilted. Remove to a cutting board and roughly chop.
In a mixing bowl, mix the ricotta cheese, ¾ italian blend cheese, shredded chicken, spinach, parmesan cheese and and egg. Spoon the mixture into a piping bag or a large Ziploc bag with the corner cut off (the hole needs to be large enough for the filling to pass through.
Ladle alfredo sauce over the bottom of a 13 x 9 rectangular baking dish.
Squeeze the filling into the manicotti tubes and arrange them side by side in the baking dish. Ladle additional sauce over the top of the pasta, and sprinkle with the remaining ½ cup of cheese.
Bake for 20 minutes. Cool slightly, sprinkle with parsley, and serve.