Using gulp-less

		
npm install --save-dev gulp-less
		
		

gulpfile.js:

		
// including plugins
var gulp = require('gulp');
var less = require("gulp-less");

// task
gulp.task('compile-less', function () {
    gulp.src('./Less/one.less') // path to your file
    .pipe(less())
    .pipe(gulp.dest('path/to/destination'));
});	
		
		

Run:

		
gulp compile-less