Over a bain-marie, whisk together the egg whites, sugar, and salt. Heat the mixture through it is smooth and creamy.
Remove from the heat and add the vanilla, flour and coconut. Cover and refrigerate for 2 hours, or until firm.
Preheat the oven to 165c (150c fan) and line two baking sheets with parchment.
Scoop small mounds of the chilled mixture on the lined baking sheets, leaving a good amount of room to let the heat circulate. Bake for 15-20 minutes, or until golden brown.
Remove from the oven and place the baking sheets directly onto a cooling rack. Allow to cool on the baking sheets for 10 minutes, before cooling completely on a wire rack.
Finely chop the dark chocolate. Take about 2/3rd of the chocolate and heat it in short burst in the mocrowave to melt it. Add in the other 1/3 of chocolate and stir until everything is melted. Decorate macaroons as desired.