Cut the butter into 1/3's

Add water to the bottom pot of a double boiler or use a pot and bowl with water in the pot.

Place over medium heat.

Add 1/3 of the butter, egg yolks, lemon juice, and water to the top of a double boiler or bowl (over pot).

Whisk at a fast pace constantly until butter melts and mixture starts to thicken.

While continuing to whisk, add the butter, one piece at a time, whisking to incorporate each time.

Cook for two more minutes, whisking constantly.

Remove from heat and serve.

If the sauce gets too thick or curdles slightly, thin out with 1-2 Tbsp. HOT water.