Preheat oven to 325F. Line a baking pan with parchment or a silicon mat.
Whip egg whites to soft peaks in a metal bowl.
Slowly add sugar, a tbs full at a time so as not to deflate your hard won air bubbles. You can add a little faster towards the end.
Fold salt, zest, and coconut flakes into the egg whites.
Place lumps of batter in heaping tbs amounts on the baking sheet. You can put them pretty close together as they do not spread much.
Bake for 18-20 minutes until golden on top.
Allow to cool on sheet for 5-10 minutes before trying to remove or you will lose the bottoms.