Melt 2 tablespoons butter in a skillet, add the green onions and cook until wilted.

Add the flour, mix well; and stir in the broth, champagne, mustard, nutmeg, and black pepper.

Bring to a boil, reduce heat, and simmer until slightly thickened, stirring frequently.

Remove from the heat and stir in the sour cream. Let cool slightly.

Grease a 9" x13" baking dish, and distribute the bread cubes on the bottom. Melt the remaining 4 tablespoons of butter and drizzle over the bread cubes. Top with the cheese and ham.

Place the eggs in a medium bowl, add a small amount of the cooked mixture to the eggs and blend well.

Blend remaining cooked mixture into the eggs. Pour the egg mixture over the bread, cheese, and ham.

Cover casserole with plastic wrap and refrigerate overnight.

Preheat oven to 350 degrees F. Uncover the casserole and place on a baking sheet.

Bake 55 minutes or until a knife inserted in the center comes out clean.