(a repost from 2006 - my early blogging days!)
I've been eating this and helping to make it, for as long as I can remember. My grandmother made it for us when we were really small, and I loved it so much I learned to make it too.
Here's how I make lemon curd (sometimes called 'lemon honey'):
5-6 juicy lemons
125g butter
2 cups sugar
4 free-range eggs
Beat the eggs briskly with a whisk and set aside. Grate the rind from all the lemons and set aside, then squeeze them and strain the juice. Set up a double boiler (I use a saucepan inside/on top of a bigger one filled with water) and inside it melt the butter. Stir in the sugar and lemon juice, until sugar is dissolved. Then add the beaten eggs and lemon rind, stirring all the time. Adjust the heat of the double boiler so that the water is moderately bubbling, then cook the lemon curd, stirring well all the time) until it becomes quite thick. It will thicken a little more on standing and when it's in the fridge, but you're aiming for a thick, smooth custard type of texture. Pour into sterilised jars. (Makes about 2 large or 3 small jars)
There are lots of ways to eat this but on toast is the best (in my opinion). You can also sandwich it between cake layers, or use it in other baking.
It's best to keep it in the fridge, both before and after opening.