Place more ice in a cocktail shaker and add the whisky, lemon juice, simple syrup and bitters. Shake for 40 seconds.
Remove the ice from the glass and add fresh ice.
Strain the cocktail into the glass and top with a dash of soda water.
Garnish with the lemon twist and mint sprig.
Don't miss a thing
Get the lowdown on our latest finds – from boutique hotels and special places to stay to events, restaurant openings and more – delivered direct to your inbox via the Food Lifestyle email newsletter.