To a medium saucepan over medium heat, add the blueberries, water, sugar, honey and lemon zest. Cook, stirring often, over medium-low heat until the blueberries soften (about 10 minutes). Mash the blueberries to release all of the juice. 

Strain the blueberries through a fine mesh sieve, pressing out as much juice as possible. Discard the leftover pulp/skin. 

Let the mixture cool to room temperature, then whisk in the lemon juice. 

Pour the mixture into a Pour it into a shallow baking dish (ours is 8x11.5", you can also use a 9x13") and freeze for about 1 hour. After 1 hour, use a fork to scrape the ice crystals and repeat this every 45-60 minutes for about 4-6 hours, or until frozen solid.

Before serving, scrape and fluff the granita again with a fork. Serve right away. Keep leftovers stored in the freezer for up to 3 months.