Amazing Breakfast Casserole

This recipe I found online didn't really have a name, so I named it.  And it truly is amazing.  : ) 

4 slices of bread, cubed (sourdough works really well!)
12 eggs
1 cup sour cream
3 green onions, chopped (reserve the green tops for garnish on top)
1 lb. ham, cut into very small cubes
1 cup milk
1 1/3 cups grated cheddar cheese, divided

Spread bread cubes evenly in bottom of a 9x13 baking dish.  Cut ham into cubes.  Cover bread with ham.  In a large bowl, beat eggs, milk and sour cream until smooth.  Stir in 1 cup of cheese and onions.  Pour mixture over ham.  Top with 1/3 cup cheese and the tops of the green onions.  Bake, uncovered at 325 for 45 minutes or until knife inserted in the center comes out clean and casserole has "puffed" up.  Let stand 10 minutes before serving. 

(As with most breakfast casseroles, this one just about always takes longer then the recommended bake time.  I usually bake it with plenty of time to spare and then just cover it to keep it hot.)