How can I list all my AWS EC2 instances using NodeJS (in Lambda)?

I'm on AWS and using NodeJS AWS SDK. I'm trying to build a Lambda function and inside I want to get a list of all my EC2 instances, but I just can't seem to get it working. Can anyone spot what I'm doing wrong?

Here is my lambda function code:

var AWS = require('aws-sdk');
AWS.config.region = 'us-west-1';

exports.handler = function(event, context) {
    console.log("\n\nLoading handler\n\n");
    var ec2 = new AWS.EC2();
    ec2.describeInstances( function(err, data) {
        console.log("\nIn describe instances:\n");
      if (err) console.log(err, err.stack); // an error occurred
      else     console.log("\n\n" + data + "\n\n"); // successful response
    });
    context.done(null, 'Function Finished!');  
};

And this is my policy (I think it's correct?)

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": [
        "logs:*"
      ],
      "Resource": "arn:aws:logs:*:*:*"
    },
    {
    "Effect": "Allow",
    "Action": [
      "ec2:*"
    ],
    "Resource": "arn:aws:ec2:*"
  },
    {
      "Effect": "Allow",
      "Action": [
        "s3:GetObject",
        "s3:PutObject"
      ],
      "Resource": [
        "arn:aws:s3:::*"
      ]
    }
  ]
}

And if I do a console.log on 'ec2' I get:

{ config: 
   { credentials: 
      { expired: false,
        expireTime: null,
        accessKeyId: 'XXXXXXXXXXXXXXXXXX',
        sessionToken: 'XXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXXX',
        envPrefix: 'AWS' },
     credentialProvider: { providers: [Object] },
     region: 'us-west-1',
     logger: null,
     apiVersions: {},
     apiVersion: null,
     endpoint: 'ec2.us-west-1.amazonaws.com',
     httpOptions: { timeout: 120000 },
     maxRetries: undefined,
     maxRedirects: 10,
     paramValidation: true,
     sslEnabled: true,
     s3ForcePathStyle: false,
     s3BucketEndpoint: false,
     computeChecksums: true,
     convertResponseTypes: true,
     dynamoDbCrc32: true,
     systemClockOffset: 0,
     signatureVersion: 'v4' },
  isGlobalEndpoint: false,
  endpoint: 
   { protocol: 'https:',
     host: 'ec2.us-west-1.amazonaws.com',
     port: 443,
     hostname: 'ec2.us-west-1.amazonaws.com',
     pathname: '/',
     path: '/',
     href: 'https://ec2.us-west-1.amazonaws.com/' } }