On a preheated 350 F, toast coconut until golden brown (12-15 minutes), shake/stir once. Cool to room temperature.
On electric mixer, beat egg whites and next 4 ingredients until foamy. Add in sugar bits by bits, and beat until stiff peaks form.
Beat in 1/4 cup boiling water, 1 tablespoon at a time, beating until whites are stiff and glossy.
Fold in toasted coconut.
Spoon batter onto a prepared baking sheet and spread with slightly raised edges and bake for 10 minutes.
Reduce oven temperature to 200°F and bake until dry and crisp outside and just cooked through inside, about 1 hour.
Turn off oven. Let meringue stand in oven 1 hour then remove from oven and cool completely.