01 - Combine sugar and water in a small saucepan. Heat over medium heat, stirring constantly until sugar completely dissolves, approximately 2–3 minutes.
02 - Remove saucepan from heat. Add fresh mint leaves to the hot syrup, gently bruising them with a spoon to release oils. Cover and allow to steep for 10 minutes.
03 - Pour syrup through a fine mesh strainer into a mixing bowl, pressing firmly to extract maximum mint flavor. Discard used mint leaves.
04 - Whisk in fresh lemon juice, cranberry juice, and lemon zest until thoroughly incorporated.
05 - Transfer mixture to a shallow freezer-safe container. Cover tightly and place in freezer for 1 hour.
06 - After 1 hour, scrape mixture thoroughly with a fork to break up ice crystals. Repeat scraping every 30–45 minutes for 3–4 hours until sorbet reaches light, fluffy consistency.
07 - Scoop into chilled bowls or dessert glasses. Garnish with fresh mint leaves and serve immediately.