menu.php

<?php
$factory = $this->container->get('ktw_database_menu.factory');

$menu = $factory->createItem('root');

$menu->addChild('Home', array('route' => 'homepage'));
$menu->addChild('About Me', array(
                    'route' => 'page_show',
                    'routeParameters' => array('id' => 42)));

// Another way to add children ...
$parentMenuItem = $factory->createItem('Parent', array('route' => 'parent_route'));
$parentMenuItem->addChild('Grandchild', array('route' => 'grandchild_route'));

$menu->addChild($parentMenuItem);

$objectManager->persist($menu);
$objectManager->flush();