Prepare the Basil Swirl: Pulverize basil leaves, 1/4 cup sugar, 2 tablespoons lemon juice, and a pinch of salt in a blender to form a smooth paste. Set aside. (A tiny drizzle on the plate, as requested in the formatting section, can also be used).

Make the Basil Simple Syrup: In a saucepan, combine 1 cup sugar and 1/2 cup water. Heat, stirring, until sugar dissolves. Steep remaining basil leaves in the hot syrup for 10-15 minutes. Strain syrup, pressing down, and let cool.

Combine Base: Whisk the cooled basil simple syrup and 1 1/2 cups fresh lemon juice together. (Optionally, add zest). Ensure mixture is cold before churning.

Churn: Pour the cold mixture into your pre-chilled ice cream maker and churn until thick and slushy (20-30 minutes).

Swirl and Freeze: Working quickly, gently fold the basil swirl paste into the churned sorbet base with 2-3 deliberate strokes. Transfer to a pre-chilled container and freeze for at least 4 hours.

Garnish: Serve three scoops in a bowl, garnish with fresh basil leaves. Drizzle a tiny drop of the green paste onto the plate for a sophisticated finish.