Add the sugar and water to a small saucepan.
Heat over medium heat, stirring until the sugar dissolves completely.
Remove from the heat and let the simple syrup cool completely.
Peel and chop the kiwis.
Add the kiwi, cooled simple syrup, and lemon juice to a blender.
Add a small amount of fresh ginger if using.
Blend until smooth.
Add a few mint leaves if desired and blend briefly again.
Pour the mixture into a shallow freezer-safe container.
Cover tightly with plastic wrap or a lid.
Freeze for approximately 4–6 hours, or until firm.
Let the sorbet sit at room temperature for about 5–10 minutes before scooping if necessary.
Scoop into serving bowls and garnish with fresh kiwi slices.
