Lightly coat the interior of a rectangular baking dish with butter
Lightly butter bread slices on both sides
Place one layer of bread slices in the pan (trim to fit)
Scatter with 1/2 of the cheese and ham, and chives, if using
Top with a second layer of bread, ham, cheese and chives
Whisk the eggs and half-and-half together with salt, pepper and nutmeg
Pour half-and-half mixture over the bread
Press down on bread to help submerge and soak up liquid
Cover with plastic wrap and refrigerate (from 2 hours to overnight)
The next day:
Heat oven to 375 degrees F.
Bake pudding until the top browns and custard set but still a bit jiggly
Let cool briefly and serve
Note: This dish can also be assembled and baked immediately – no need to refrigerate.