If using fresh lemon zest, thoroughly zest lemons and spread out on a baking sheet lined with parchment paper. Put oven on the lowest setting and leave until completely dried. Mine took 35 minutes at 170 degrees. When completely dried, remove from oven.
In a food processor, place peppercorns and grind down to coarse texture.
Add sea salt and grind mixture again.
Add lemon zest and pulse to combine and get to finer consistency.