Preheat the toaster oven or oven to 170˚F. Line a small baking sheet with parchment paper.
Place the lemon zest in a single layer on the prepared baking sheet and place in the oven until the lemon zest is dried completely, about 60 minutes. Allow the lemon zest to cool completely.
Transfer the lemon zest along with the peppercorns and salt into a spice grinder or a small high-powered blender and pulse a few times until the mixture is combined but still has some coarse texture. (note I over processed mine and it was too fine)
Store in an airtight container in a spice drawer for up to six months.