Melt the dark chocolate.
Spoon melted chocolate into the bottom third of the rose mold cavities (you can also use a piping utensil).
Insert a grape into each hole (make sure they are completely dry).
Top with more chocolate, ensuring the grapes are fully covered.
Allow to set in the fridge.
Remove each rose grape carefully from the mold.
Arrange the chocolate grape roses in a bowl or on a platter.
Serve.