Simple Hollandaise Sauce

• 100 g (4 oz) unsalted butter
• 1 egg yolk
• ½

Make clarified butter by melting the butter in a pan and then leaving it to cool slightly so that it is just warm when added to the sauce; the sauce will curdle if it is too hot. The butter should have separated; add only the clear butter oil to the sauce, not the buttermilk that will have collected at the bottom of the pan.

Add the egg yolk to the water in a bowl and whisk over a pan o