When the water comes to a boil, place a mixing bowl
(prefer metal) over top of the pot. Be careful not to let
the bowl touch the water.
In the bowl (over the boiling water) whisk together the
egg yolks, lemon juice, and water until pale yellow in
color. Keep the mixture moving to keep the eggs from
cooking.
Remove the bowl from the pot and whisk vigorously..
Add the butter, 1 teaspoon at a time, until it is all
incorporated.