Mist a frozen cocktail glass with pastis and set aside.
Add the gin, Grapefruit-Lavender Cordial, Lillet and bitters to a mixing glass and fill with ice.
Stir, and strain into the prepared glass.
Twist the lemon peel over the drink to extract its oils and discard.
Garnish with a swatch of lemon peel and a lavender sprig on a cocktail pick.