1. In a saucepan, saute the scallions in butter until tender. Whisk in flour; whisk in milk all at once. Bring to a boil and cook and stir until the sauce is thickened and bubbly.

2. Meanwhile, combine the cracker crumbs (breadcrumbs work too in a pinch) and cheese. Dip chicken breast halves in the crumb mixture to coat lightly; retain remaining crumb mixture. (Note: If freezing the meal for later, seal the remaining crumb mixture in a freezer bag).

3. Arrange the breast halves in a greased 13 x 9-inch baking dish.

4. Stir the spinach and ham into the white sauce. Spoon the spinach mixture over the chicken. (Can freeze at this point for later; tape the crumb mixture bag to the side. Defrost before baking.).

5. Bake, covered, at 350F for 60 to 75 minutes. Uncover and sprinkle with crumbs. Bake 10 minutes more.