In a medium saucepan, combine 1 cup of granulated sugar with 1 cup of water. Heat over medium heat, stirring occasionally, until the sugar is fully dissolved, about 3-5 minutes.

Once the sugar is dissolved, add a generous handful of fresh basil leaves to the syrup. Gently immerse the leaves and let simmer on low heat for 10-15 minutes.

Remove from heat and let the basil steep for at least 30 minutes to absorb the flavor.

Strain the syrup through a fine sieve into a clean container to remove basil leaves. Allow cooling at room temperature for about 15-20 minutes.

While the syrup cools, roll fresh lemons to release more juice, then juice them, straining out seeds. You’ll need about 1 cup of juice.

In a large pitcher, combine the cooled basil syrup, freshly squeezed lemon juice, and about 4 cups of cold water. Stir well to mix.

Refrigerate for at least 30 minutes to chill and let flavors meld.

Serve over ice and garnish with lemon slices and basil sprigs.