My Mom who was a wonderful cook, made and served this every Christmas since I was young. I carried on the tradition and made it for my Son and now my 4 Grandkids every Christmas. Every now and then the kids will ask me for Christmas Breakfast for dinner!
Cut bacon into 1" pieces, separate and fry slowly in large skillet until crisp. While cooking bacon, trim ends and all but 3 inches of green part of leeks. Slice the white and remaining green parts in 1/4 inch slices and soak in cold water to clean. Rinse, drain, and pat dry the cleaned leeks.
When bacon is crisp, remove to drain and discard all except a couple of tablespoons of the drippings. Add the drained leeks to the bacon drippings and saute until very soft but still green. Remove from heat to cool slightly.
Beat the eggs, milk, nutmeg, salt and pepper until thoroughly blended.
Add the bacon, ham, shredded swiss, to the leeks. Mix in the milk/egg mixture and pour all into a 3 quart buttered casserole (I prefer a deeper round one but doesn't have to be).
Bake at 350 for 45 min to an hour, depending on the depth of your dish. Allow to "rest" for a few minutes before cutting.