Pour the water into a large saucepan; bring to a boil. Stir in sugar until dissolved. Remove from heat. Cool to room temperature.
Combine the kiwi, sugar syrup, lemon juice and salt in a blender. Purée until smooth. Pour into a 9-inch square metal baking pan. Freeze for 4 hours or until firm.
Break into chunks and place in a food processor. Pulse until smooth and scrape into an airtight container. Freeze for an additional 4 hours or until set.
Scoop into dessert dishes and garnish with coconut if using.
Tip: Sorbet can be stored in the freezer for up to 1 week.
