Tip the sugar and 150ml water into a saucepan set over a low heat and heat until all the sugar has dissolved. Turn up the heat to medium-low and add the cranberries. Cook, stirring occasionally for 15 mins or until the cranberries have started to break down. Leave to cool, then blitz to a smooth purée using a hand blender, if you like (you can also leave it as is). Will keep in a sterilised sealed jar in the fridge for up to a week.

To serve, spoon 1 tbsp of the cranberry purée into each glass, stir in a measure of the gin and top up with the soda water. Garnish each glass with an orange slice and add a few ice cubes. Alternatively, mix everything together in a jug and serve.