Method

• 1.
  To make the basil oil, place oil and basil in a small saucepan over medium heat and cook, stirring occasionally, until warm (82°C if using a thermometer). Transfer to a heatproof blender and, with the steam cap on, whiz for 1 minute, or until smooth and combined. Season to taste. Leave to strain at room temperature through 2 layers of muslin or a coffee filter into a jug or bowl. Let it drip for 2-3 hours (do not press down on puree, as this will push through some of the puree, and will oxidise and discolour your oil). Store in a jar in the fridge.
• 2.
  Meanwhile, place the tomato and a pinch of fine salt in a small food processor and whiz until a puree. Place a fine sieve over a small jug. Pour the puree into the sieve, then place a small bowl on top to weigh the puree down (do not press down on puree, so the liquid is clear). Stand for 2 hours to slowly drain.
• 3.
  For the cocktail, place a coupe glass in the freezer. Combine gin, vermouth, lemon juice and 80ml tomato water in a cocktail shaker filled with ice cubes. Cover and shake vigorously until chilled.
• 4.
  Strain into chilled glass. Add a few drops of basil oil. Finish with a sprinkle of black pepper and garnish with cherry tomatoes.