Makes 1 litre

For the rhubarb syrup
200g caster sugar
300ml water
2 (150g) medium rhubarb stems, washed, trimmed

200ml gin
200ml rhubarb syrup
500ml tonic water
Ice, to serve
10 lime slices, to serve
Mint leaves, to serve

To prepare the rhubarb syrup, place the sugar and water into a saucepan and bring to the boil, reduce the heat and simmer for 6 to 7 minutes until a light syrup forms.
Slice the washed trimmed stems into 3cm lengths and add the rhubarb to the syrup, leave to simmer for at least 6 minutes. Switch off and leave to cool completely.
Pour the syrup through a fine sieve and retain the cooked rhubarb pieces for a dessert or over yoghurt.
Pour the syrup into a sterilised bottle and keep it in the fridge. It will keep for up to 2 weeks in the fridge.
When ready to serve, add the gin to a pretty jug, add rhubarb syrup, the ice, lime slices and mint leaves.
Give it a stir and top up with the tonic water. Serve immediately.