1) whisk together the five dry ingredients into a large bowl. In a medium bowl, whisk together yolks, buttermilk, melted butter, and soda water.
2) For egg whites, add whites to a clean metal bowl and whisk with a clean whisk until the whites form medium peaks.
3) Using a flexible rubber spatula, gently fold the egg whites into the batter to lighten it. Don’t stir. Fold.
4) Heat up waffle iron, chop ham, and grate cheese.
5) Add batter to your waffle iron. The amount will vary depending on your iron but will probably be 1/2-3/4 of a cup. Sprinkle batter on top with about a tablespoon or two of ham and cheese.
6) Cook waffle according to machine instructions until golden brown, about 4-5 minutes.
7) Remove waffle. You might have to use a fork or knife to help it out.
8) Serve waffle with butter and honey or syrup or keep waffles warm in a 250 degree F. oven while you make more.