top. place 5 egg whites and 2/3 cup of sugar into the heat proof bowl that can fit on top of the sauce pan without touching the water. using a wire whisk, stir the egg sugar mixture continuously till you don't feel any sugar crystals when rubbing the mixture between your fingers. at this point you can notice that the egg sugar mixture is clear with light pale color. if you have a candy thermometer, it should read 160°f which makes the egg whites safe to use. turn off the flame.
now add the cold butter pieces one at a time and whip till the butter is mixed well with the 