Fill your food processor with hot water; set aside.
Melt the butter in a small saucepan over medium heat until foaming. Remove the pan from the heat.
Drain the food processor and dry well.
Put the egg yolks and two tablespoons of lemon juice in the processor. (The picture here shows the small white plastic blade, but I found that the larger metal blade works better.)
Cover and combine.
Working quickly and with the processor running, pour the hot butter VERY SLOWLY into the processor in a thin stream of droplets, discarding the milk solids in bottom of the saucepan. (The egg yolks aren't raw: the hot butter cooks them.)
Blend until a creamy sauce forms.
Season it to taste with salt and pepper and more lemon juice, and serve immediately.
What if my hollandaise "breaks"?
Sometimes the sauce doesn't get thick. This usually happens because you added the butter a little too quickly. Don't worry... you can fix it.
Scrape the hollandaise well out of the food processor and into another bowl. You don't have to wash out the processor.
Put another egg yolk in the food processor bowl and blend it until it's smooth (you may add a little more lemon juice if you wish).
As the processor runs, pour the loose hollandaise into the yolk SLOWLY, in a thin stream of droplets, until it achieves the desired thick texture.
April 24, 2011 Made for asparagus for Easter dinner — perfect. Soft, and got firmer as it cooled. Easy and delicious. Epicurious.com, Bon Appétit, May 2011