Preheat oven to 400 degrees F (200 degrees C).
In a small bowl, combine Part-Skim Ricotta Cheese (1/2 cup), Mozzarella Cheese (1/4 cup) and Parmesan Cheese (2 tablespoon). Mix well.
Drain Spinach Leaves (1 cup) and spread one-fourth of it over Chicken Cutlet (4). Spread cheese mixture over the spinach. Starting with the short end, tightly roll up cutlets, jelly-roll style.
In a medium nonstick skillet, melt Butter (1 teaspoon) over medium-high heat. Add cutlets; cook turning frequently, until browned, about two minutes. Place in a baking dish.
To prepare sauce, in a small bowl, stir together Non-Fat Milk (3/4 cup), Chicken Broth (1/2 cup), and Corn Flour (1 tablespoon).
Melt Butter (1 teaspoon) in the same skillet over medium heat. Add milk mixture; cook, stirring constantly until mixture boils. Remove from heat. Stir in Cheddar Cheese (3/4 cup). Pour over cutlets.
Bake until browned and bubbling, about 15 minutes.
Serve chicken immediately.