The easiest way to get perfect Hollandaise sauce is to use a blender. This recipe has all the same ingredients as the classic, but no double boiler and no chance of the sauce separating.

Original recipe yields 6 servings

• 3 egg yolks
• ¼ teaspoon Dijon mustard
• 1 tablespoon lemon juice
• 1 dash hot pepper sauce (e.g. Tabasco)
• ½ cup butter (1 stick)

1. In the container of a blender, combine the egg yolks, mustard, lemon juice and hot pepper sauce. Cover, and blend for about 5 seconds.
2. Place the butter in a glass measuring cup. Heat butter in the microwave for about 1 minute, or until completely melted and hot. Set the blender on high speed, and pour the butter into the egg yolk mixture in a thin stream. It should thicken almost immediately. Keep the sauce warm until serving by placing the blender container in a pan of hot tap water.

source: https://www.allrecipes.com/recipe/84214/blender-hollandaise-sauce/