Meteor: Calling an asynchronous function inside a Meteor.method and returning the result

Use a Future to do so. Like this:

Meteor.methods({
  my_function: function(arg1, arg2) {

    // Set up a future
    var fut = new Future();

    // This should work for any async method
    setTimeout(function() {

      // Return the results
      fut.ret(message + " (delayed for 3 seconds)");

    }, 3 * 1000);

    // Wait for async to finish before returning
    // the result
    return fut.wait();
  }
});

Update:

To use Future starting from Meteor 0.5.1, you have to run the following code in your Meteor.startup method:

Meteor.startup(function () {
  var require = __meteor_bootstrap__.require
  Future = require('fibers/future');

  // use Future here
});

 
Update 2:

To use Future starting from Meteor 0.6, you have to run the following code in your Meteor.startup method:

Meteor.startup(function () {
  Future = Npm.require('fibers/future');

  // use Future here
});

and then use the return method instead of the ret method:

Meteor.methods({
  my_function: function(arg1, arg2) {

    // Set up a future
    var fut = new Future();

    // This should work for any async method
    setTimeout(function() {

      // Return the results
      fut['return'](message + " (delayed for 3 seconds)");

    }, 3 * 1000);

    // Wait for async to finish before returning
    // the result
    return fut.wait();
  }
});

See this gist.