The command line is trustworthy, dependable and clean. Conversely, GUIs are slow and cranky. This tech-recipe desribes how to burn an ISO image from the command line on a Mac. There is a way to do this with GUI, but you can be burning the disc before that GUI starts up.
Given an ISO file (image.iso, for example) in the current working directory, use the following command to burn it to a disc that you’ve inserted into a recordable drive:
hdiutil burn image.iso