Line Jelly Roll pan with foil and spray with non-stick spray.
Thaw and squeeze moisture from spinach.
In blender, puree spinach, eggs, whipping cream, garlic and Parmesan cheese until smooth. Pour into prepared pan.
Bake at 350°F for 8-10 minutes.
Lift foil with baked spinach mixture and place on working surface.
While spinach is cooling sauté chicken, peppers and scallion; season to taste.
When spinach is still warm sprinkle with mozzarella cheese all over, add sliced chicken, peppers and onions. Roll up starting with short end. When you have a complete roll, cut (you should get about three separate rolls out of this one pan). Can be sliced in 1/2" or smaller pieces for appetizer.