For the thyme syrup, heat sugar, water and thyme sprigs in a medium saucepan over medium-high heat until mixture comes to a boil, about 5 to 6 minutes. Remove from heat and let cool. Discard thyme sprigs.
For the celery juice, blend celery and water in a blender on high for one minute. Strain mixture through a fine mesh strainer or sieve. Alternatively, if you have a juicer, nix the water and simply juice the celery through the juicer.
For the Celery Gin Thyme Cocktail, place gin, celery juice, thyme syrup and lime juice in a shaker with ice. Shake and strain into a glass over ice. Top with a splash of tonic water and garnish with a celery stalk.
Recipe by Allons-Eat! at https://www.allonseat.com/celery-gin-thyme-cocktail/