1Separate the yolks from the whites and put the yolks into a glass bowl
2Melt the butter in a saucepan
3Put the bowl with the eggs over a pan of simmering water
4And 1 tablespoon lemon juice and 1 tea spoon of mustard
5Whisk well and gradually add in the butter. Jamie's Tip: Keep an ice cube readily available at this stage. If you can see that the mixture is starting to split, drop in the ice cube and whisk it in. This can save the hollandaise sauce!