If you don't already have honey syrup, combine equal parts honey and very warm water (1:1 by volume) and stir until fully combined. Cool slightly before using.

Dry shake

In a cocktail shaker, add the gin, fresh lemon juice, honey syrup, orange liqueur, fresh grapefruit juice, egg white, and two dashes of Angostura bitters. Seal the shaker and shake vigorously without ice for 15–20 seconds to emulsify the egg white and build a silky foam.

Wet shake

Open the shaker, add the ice, reseal, and shake again very hard for 12–15 seconds until the shaker is well chilled and the exterior is frosty. This second shake chills and dilutes the drink and further aerates the foam.

Double strain and serve

Double strain the cocktail into a chilled coupe or Nick & Nora glass using a fine mesh strainer and the shaker strainer to remove small ice shards for a silky texture. Allow the foam to settle on top.

Garnish

Float the thin grapefruit wheel on the foam, place the micro basil leaf gently on top of the wheel, and finish by grating a small amount of lemon zest over the foam to release bright citrus oils. Optionally add a single extra dash of Angostura on the foam in a small pattern for aroma and visual contrast.