- Bring 2 cups water to a boil in medium nonreactive saucepan.
- Add the lemon juice, zest, and Sugar.
- Simmer to blend flavors, about 30 minutes.
- TO FREEZE: Transfer syrup to medium nonreactive bowl; cool to room temperature.
- Freeze, stirring every 30 minutes to incorporate frozen portion of mixture back into the syrup.
- As mixture freezes, scrape spoon across the nearly frozen mixture to break it up.
- Repeat scraping process every 30 minutes until mixture is just solid, 3 to 4 hours.
- GARNISH: Cut the zest of a large lemon into fine julienne strips.
- Cover with water and boil for 5 minutes; drain.
- Bring 1 cup Sugar, 1/3 cup corn syrup and 1/3 cup water to boil.
- Remove from heat, stir in zest, and let stand for 30 minutes.
- Transfer zest to wire rack.
- After 15 minutes, when zest feels dry, roll it in additional Sugar.
- Can be stored in an airtight container for up to 1 week.
- SERVING: Scoop granita into chilled serving glasses garnish with candied lemon zest and serve immediately.