Preheat the oven to 350°F. Line two baking sheets with parchment paper.
Use a thoroughly cleaned mixer and whisk to whip the egg whites until they are at stiff peaks. Set aside.
In a bowl, mix together the condensed milk, coconut, cocoa powder, and salt until well combined.
Fold in the whipped egg whites.
Use an ice cream scoop to create small rounds of the mixture and place on the baking sheet with some space between them. The cookies do not spread, but need some space for even baking.
Bake for 20 - 25 minutes or until you can lift one up without anything sticking to the parchment paper.
Melt your chocolate. Dip the bottoms of the macaroons into the chocolate. Place on the parchment paper.
If you have any leftover chocolate, you can drizzle it over the top of the macaroons.
Chill the macaroons for 5 minutes for the chocolate to set.
Store in an airtight container.
Notes
You'll need just under the full can of sweetened condensed milk. This is one time I will say it is okay if you are not entirely precise and just take out about 2 tablespoons out of the can before pouring the rest in