While oven preheats, spray a skillet with cooking spray and over medium high heat, saute the ham, garlic and onions for about 5 minutes. Remove from heat and let cool.
Place the bread cubes on a baking sheet and bake for about 15 minutes until golden brown, turning occasionally.
In a large bowl, whisk together the eggs, milk, Dijon mustard, salt, pepper and nutmeg. Add the ham mixture and the bread cubes and stir to combine.
Spray an 8 inch baking dish with cooking spray and add half the ham and bread mixture. Sprinkle half of the cheese over it. Top with the rest of the ham mixture.
Bake for 25 minutes, top with the rest of the cheese and bake for 20 minutes more.
Video
Notes
Eggs - can use egg substitute - use ¾ cup.Bread - use whatever leftover bread you have available. Cheese - other good choices are smoked gouda and fontina.