Using a rubber spatula, spread the chocolate fudge sauce evenly over the pie crust. Set it in the freezer to harden. Remove the sherbet from the freezer to soften. In a medium bowl, combine the sherbet and the chips with a large spoon. Remove the crust from the freezer. Spoon the sherbet mixture on the crust. Smooth the top with spatula. Return to the freezer until ready to serve.