Pre-heat the oven to 200°F.
Line a baking sheet with aluminum foil; the foil will make it easy to pour into the grinder later.
Mix the salt, ½ cup rosemary and lemon zest on one side of the foil-lined tray.
Place only ¼ cup rosemary on the other side of the tray.
Be very careful not to mix these two piles together at this point.
Place in the pre-heated oven for 20 minutes.
Remove from the oven and let cool to room temperature.
Form foil into a funnel for an easy and mess-free pour into a coffee grinder.
Add the salt, ½ cup rosemary, and lemon zest to a coffee grinder and coarsely blend.
Be careful not to over grind or you’ll end up with powder; pour into an airtight container.
Blend remaining ¼ cup rosemary in coffee grinder until it becomes a powder.
Pour into the same container with the coarse salt mixture, cover and shake to blend.
Store in an air-tight container.