Cover a sheet pan with waxed paper. Place chocolate chips and shortening in medium heat-proof bowl. In separate large heat-proof bowl, add very warm water (100 to 110 degrees F) to 1-inch depth. Carefully place bowl with chocolate into bowl of water. The water should come halfway up side of chocolate bowl. Stir chocolate and shortening constantly with dry rubber scraper until chocolate and shortening are melted and mixture is smooth. Do not get water into the bowl with chocolate. (If water cools, replace it with very warm water as directed above; water temperature is important to success). Remove chocolate bowl from inside water bowl. Remove the filling from molds and place on the waxed paper lined sheet pan. Pour chocolate mixture over the filling, and remove excess chocolate from around the filling. Refrigerate coated bombs for 1 to 2 hours before serving. Garnish, as desired.