In Casino Royale, Bond orders not a vodka martini (shaken) but a drink he later names the Vesper:
'A dry martini,' he said. 'One. In a deep champagne goblet.'
'Oui, monsieur.'
'Just a moment. Three measures of Gordon's, one of vodka, half a measure of Kina Lillet. Shake it very well until it's ice-cold, then add a large thin slice of lemon peel. Got it?'
'Certainly monsieur.' The barman seemed pleased with the idea.
'Gosh, that's certainly a drink,' said Leiter.
Bond laughed. 'When I'm ... er ... concentrating,' he explained, 'I never have more than one drink before dinner. But I do like that one to be large and very strong and very cold, and very well-made. I hate small portions of anything, particularly when they taste bad. This drink's my own invention. I'm going to patent it when I think of a good name.'
Casino Royale, by Ian Fleming
This gives us a 3:1:0.5 ratio of gin to vodka to Kina Lillet. Kina Killet's recipe has changed over the years, dropping the bitter quinine. I've added Angostura bitters to make up for the bitter flavour of quinine.
Ingredients
Sipsmith VJOP gin
Kina Lillet
Angostura bitters
preferred citrus peel
Recipe
Several hours ahead of desired drinking, mix a 3:1:0.5 ratio of the primary three ingredients, and freeze. (Freezing early neatly avoids the gin-bruising and dilution arguments introduced by ice.)
To serve, pour into a glass of choice. Add two dashes of bitters (or to taste), citrus peel, and sip pensively.
The result is a smokey, botanical tension reliever, with notes of tea and citrus. Sometimes I enjoy the aesthetic of tiny ice flecks floating in the drink, so I'll shake it gently with ice before serving.
I've made this in bulk and kept it in the freezer, adding bitters and peal when I serve without discernible loss of quality (or enjoyment).