Preheat the oven to 325°F.
Toast the cashews on a baking sheet in the preheated oven for 20 minutes until uniformly golden brown.
Cool the nuts to room temperature.
Toast the coconut on a baking sheet in the preheated oven until lightly golden around the edges, about 10 minutes.
Cool the coconut to room temperature.
Heat 1 inch of water in the bottom half of a double boiler over medium heat.
With the heat on, place the semisweet chocolate in the top half of the double boiler.
Use a rubber spatula to stir the chocolate until completely melted and smooth, about 5 to 6 minutes.
Transfer the melted chocolate to a 4-quart bowl.
Add the cashews and coconut.
Use a rubber spatula to stir the mixture until the cashews and coconut are completely coated with chocolate.
Immediately portion 24 clusters, 1 heaping tablespoon (approximately 1 1/2 ounces) of mixture per cluster, onto wax paper.
Allow the clusters to harden at room temperature for 1 hour, then refrigerate for 30 minutes until firm enough to handle.
Store the clusters in a tightly sealed plastic container in the refrigerator until ready to serve.
The clusters will keep in the refrigerator for several days.