This healthy update of a traditionally rich ham-and-cheese breakfast strata is made lighter primarily by losing a few egg yolks and using nonfat milk. Gruyere cheese has a delicious, nutty aroma and flavor, which means that with the relatively small amount in this recipe you still get a big impact. To finish the makeover use nutritious, fiber-rich, whole-grain bread instead of white. The results: plenty of flavor, half the calories and one-third the fat of the original.