This elegant martini variation is a creation of Sir Ian Fleming, or rather his penned character James Bond. It is a mixture of Kina Lillet (unfortunately discontinued from 1986) plus a combination of gin AND vodka, with a lemon peel garnish.
It’s quite a subtle variation, named after the femme fatale bond girl Vesper Lynd, played by the incredibly beautiful Eva Green in the 2006 film Casino Royale.

Ingredients
3 measures of gin
1 measure of vodka
Half a measure of Kina Lillet*
*This is the original recipe, so in the absence of Kina Lillet, use Lillet Dry, or substitute with another good quality dry vermouth if you can’t obtain Lillet.

How to pour
Ensure that your gin, vodka and glasses are well chilled. If they have been kept in the freezer for a sufficient amount of time you can pour this drink directly into the glass (first the vermouth, then the vodka, then the gin) and stir it with a thin slice of lemon peel.
However, for some Bond authenticity, fill a shaker with around a third of ice. Add the vermouth, vodka then gin and shake vigorously until the exterior of the shaker is very cold and the drink is well mixed, chilled and aeriated.
Strain into a martini glass and garnish with a thin slice of lemon peel as per the instructions.
If you prefer your martinis stirred, that was deemed inconsequential by Daniel Craig’s portrayal of the international spy, so mix it how you like it.