La Marga Sympa !

In a shaker, pour all the ingredients out, except the Tonic.

Add ice and shake well for 8 to 10 seconds.

Strain into an Old Fashioned glass.

Add a large ice cube.

Top with the grapefruit 1642 Tonic.

Stirr gentely with a mixing spoon.

Cheers !

Prepare the grapefruit: Wash the grapefruit well. Finely grate the zest, leaving the white part intact. Then squeeze the grapefruit to extract the juice.

Heat the mixture: In a saucepan, combine the water, sugar, grapefruit zest, juice and crushed cardamom pods. Heat over low heat, stirring until the sugar has dissolved. Bring to the boil, then simmer for 10-15 minutes over medium heat.
Strain and bottle: Remove the pan from the heat and allow to cool slightly. Strain the syrup and pour into a clean bottle.