Add the yolks to a blender. Put the top onto the blender but remove the middle piece.

Pre-heat a small frying pan over medium heat. Add the butter and let it melt. Continue heating until it bubbles and stops foaming.

Turn the blender on low and begin pouring the hot butter into the blender - very slowly at first, and then a little faster as the Hollandaise begins to emulsify

Add the lemon juice and pepper and turn the blender to a faster speed. Scrape down the sides and add the middle back to the top of the lid. Let the sauce sit in the blender until ready.

To Reheat refrigerated leftover Sauce: While reheating Hollandaise is never advisable, it can be done. Place the Hollandaise out on the counter to come to room temperature. Heat a pan of water almost to a simmer and turn off the heat. Put the container (heat proof) with the Hollandaise into the pan and let it sit in in the water until it warms. Stir. Place in the microwave for 5 seconds. Stir and check the sauce. Maybe heat for 5 seconds more, but don't push it. Serve.