grunt-contrib-less with yeoman

README.md

npm install grunt-contrib-less

##configure the Gruntfile.js file in your yeoman project

add to the top of the file

grunt.loadNpmTasks('grunt-contrib-less');

add the less task

// compile less to css
less: {
  style: {
    src: 'app/styles/premium-pixels.less',
    dest: 'app/styles/premium-pixels.css'
  }
},

In the watch object

less: {
    files: [
      'app/styles/*.less'
    ],
    tasks: 'less reload'
},