This is so simple that it hardly warrants a whole post. Whizz one up if you want to add zing and a pop of colour to all sorts of puddings: chocolate roulade, meringues with fruit and cream, even a lemon tart.
1 tbsp lemon juice
3 tbsp icing sugar
Put all the ingredients in a small food processor or use a stick blender to blitz until very smooth.
Set a sieve over a jug or a bowl. Tip the mixture into the sieve and stir / push through the liquid using a spoon or a spatula. Discard the seedy pulp left in the sieve. Decant to a jug and serve. Any leftovers will keep in the fridge for a couple of days.