Yuzu, lemongrass and ginger syrup

1. Tip the sugar into a medium saucepan with 350ml water. Lay the lemongrass on a chopping board; flatten with the flat side of a long knife. Roughly chop the lemongrass and add to the pan with the ginger.

2. Set the pan over a low heat to dissolve the sugar. With the heat very low (the syrup should only just bubble), cook for 20 minutes to infuse.

3. Increase the heat and simmer until the syrup has reduced by a third (about 15 minutes). Add the yuzu juice and simmer for 5 minutes to further reduce the syrup. Remove from the heat and leave to stand for 1 hour before straining into small sterilised bottles.