Method

• 1.
  Place the butter in a large microwave-safe jug and cover tightly with two pieces of plastic wrap. Microwave on high in 30-second bursts for 1 minute or until melted. Set aside for 3 minutes to cool slightly and for the milk solids to settle on the bottom of the jug.
• 2.
  Place egg yolks, lemon juice and 1/2 tsp salt flakes in a tall cylindrical jug. Using a handheld stick blender, blitz until just combined and smooth.
• 3.
  Without disturbing the milk solids that have settled to the bottom, slowly pour in the melted butter in a thin and steady stream, blitzing and moving the stick blender straight up and down as you go. Continue adding the melted butter until the mixture is very thick, making sure to leave behind all of the white milk solids that have settled. Season, then serve.