Separate egg whites from eggs. Place egg whites in a separate bowl. Beat egg whites until stiff, like meringue.
Beat milk, water and egg yolk in a separate bowl. Add this mix into flour, baking powder and salt in another bowl. Mix until blended. Add melted butter slowly. Mix until blended.
Fold egg white mixture into flour mixture by spatula. There should still be lumps of the beaten egg whites in the mix.
Take a measuring cup, and measure out one cup of batter to place on waffle iron. Cook until golden brown.
Can also be used to make pancakes!