1) Squeeze two lime wedges into a balloon glass and drop them in. Add the elderflower cordial, gin, and rosso vermouth. Swirl gently to combine. 2) Fill the glass to the top with cubed ice and stir for 10–15 seconds to chill and dilute. 3) Top with 75ml Fever-Tree Ginger Ale and stir once more gently to integrate without losing carbonation. 4) Garnish with a thin slice of fresh ginger snapped between the fingers to release its oils, and a slapped mint sprig held briefly over the glass to awaken its aroma before placing.
Slapping the mint sprig against the back of your hand rather than the palm releases its essential oils without bruising the leaves - you get the aroma without bitterness. Snapping the ginger slice rather than cutting it fresh at the bar is the same principle: volatiles release on the break.
My Bar Shelf reads your shelf and shows you every cocktail you can make from what you already own, including The Laverstoke.