Step 1.
- Fill a shaker with ice.
Step 2.
- Add gin, fresh lemon juice, and simple syrup to the shaker.
Step 3.
- Shake well until chilled.
Step 4.
- Strain the mixture into a highball glass filled with ice.
Step 5.
- Top with sparkling water to taste.
Step 6.
- Garnish with a lemon wheel and serve.