To infuse the gomme, add the syrup to a pan with the spices. Bring to the boil, remove from the heat and allow to cool

Prepare the glasses in advance by freezing, adding a dash of grenadine and swirling to coat. Sprinkle with caster sugar and place back in the freezer until required. Alternatively, dip the rim of the glass in grenadine followed by the caster sugar to coat the rim

Fill a shaker to halfway with ice cubes. Add the gin, 15ml of infused gomme syrup, lemon juice and egg white. Seal with a lid or Boston glass and shake hard for 30 seconds

Use a Hawthorne strainer to hold back the ice and pour through a fine strainer into the prepared champagne flute. Top up with the the tonic and garnish with glacé cherries and serve