I tried to use grunt as you say with the tutorial, but it didn't work. They say they are using a stripped down version of MEAN, so maybe they took that out? Do you know a good tutorial on adding it back in, as I like the sound of the functionality you're talking about...
For anyone else trying to add grunt, you need to copy over the gruntfile.js and add the grunt dependencies to the dev section of package.json in the root directory of the project. Then you might also have to remove and reinstall the grunt nodemon package (grunt threw up instructions on how to do this when I first ran it)