Whisk the egg yolks and lemon juice together in a heavy bowl until lightened. In the meantime, bring a saucepan of water to barely simmering. Put the bowl on top (bowl should not touch water) and continue whisking until eggs reach 160 degrees F. Remove from heat, but do not let the eggs sit. Working quickly, add the mustard and either:
When finished, blend in the pinch of cayenne and taste for salt, adding a pinch if needed.
Keep warm until serving.
Keywords: Breakfast or Brunch Dish, Hollandaise Sauce, Lemon, Sauce