01 - Combine sugar, 1 cup water, and mint leaves in a small saucepan. Bring to a simmer over medium heat, stirring constantly until sugar completely dissolves. Remove from heat and let steep for 10 minutes to infuse mint flavor.
02 - Pour the mint syrup through a fine mesh strainer into a large bowl, pressing firmly on the leaves to extract maximum flavor. Discard the spent mint solids.
03 - Add the remaining 1 cup cold water, lemon juice, cranberry juice, lemon zest, and salt to the strained syrup. Whisk thoroughly until all ingredients are fully incorporated.
04 - Transfer the mixture to a shallow metal pan or freezer-safe container. Place in the freezer for 1 hour to begin the freezing process.
05 - Remove from freezer and use a fork to scrape the frozen edges toward the center, breaking up any ice crystals. Return to freezer immediately.
06 - Continue scraping every 30-45 minutes for 3-4 hours total, until the sorbet achieves a light, fluffy, and uniform texture throughout.
07 - Scoop the finished sorbet into chilled bowls. Garnish with fresh mint leaves and lemon slices if desired. Serve immediately while firm.