Set a large bowl over a pot of simmering water.
Put 250g of butter into the bowl to melt while you prepare the other ingredients, add them when the butter has melted.
Beat 8 fresh eggs with a pinch of salt until smooth, strain through a sieve.
Take the zest off 8 clean lemons then juice them – you need one cup of juice.
Add the zest, juice, eggs and two cups of sugar to the melted butter and stir well. Cook over the simmering water until thick, stirring regularly. This will take about 25 minutes. Pour into sterilized jars and cover with a clean lid. Store in the fridge as soon as it has cooled. They will keep for a couple of months. This quantity makes enough for 4-5 medium jars.