Juice fresh lemons until you have enough juice to highlight the tartness. Finely chop fresh basil leaves using the chiffonade technique. Set aside both.

In a medium saucepan, combine filtered water and granulated sugar, stirring over medium heat until the sugar completely dissolves (3-5 minutes). Remove from heat and cool slightly.

Once cooled, pour in the lemon juice and chopped basil, stirring well to combine.

Cover the mixture and chill in the refrigerator for at least 4 hours.

Pour the chilled mixture into your ice cream maker and churn according to the manufacturer's instructions (about 20-30 minutes).

Transfer the sorbet to an airtight container, smooth the top, seal tightly, and freeze for an additional 3-4 hours.