Recipes by Di Swann
1. Put butter and sugar into a stainless steel bowl or double saucepan. Place the bowl over a saucepan of boiling water and heat until the butter has melted.
2. Add lemon zest and juice. Stir while gradually adding the beaten egg yolks.
3. Stir continuously over simmering boiling water until the mixture thickens. This will take about 15 minutes.
4. Remove from the heat and pour into clean sterilised jars. If wished the mixture can be strained prior to filling to remove the zest and any traces of cooked egg white.