1. Put 7-8 ice cubes in a cocktail shaker or medium-sized jug, add 15ml extra dry vermouth,
stir about 20 times, then add 75ml London dry gin and 60ml pomegranate juice drink.
Stir gently and strain into a Martini glass.
2. For the garnish, put 4 blackberries in a sieve. Use a fork to mash;
push the pulp and juice through the holes into a bowl. Stir through 1 tsp icing sugar until dissolved.
Drizzle around the rim of the glass. Slice into 3 blackberries and place on the side of the glass. Finish with a mint sprig.