Place chocolate in a large heatproof bowl. Bring heavy cream to a boil in a small saucepan. Add 1/4 of the cream to the chocolate and stir with a spatula until the chocolate begins to melt. Continue adding the cream, in three batches, stirring after each addition, until the chocolate is melted and the mixture is smooth and shiny. Place plastic wrap directly on the surface and keep at room temperature until ready to use.