Symfony Doctrine One to Many Validation - validation

Question

I'm wanting to validate all the images that are linked to the entity by one to many relationship with the KitchenImage table.
Here's my controller function:
public function addAction(Request $request)
{
// Check for POST
if ($request->getMethod() == 'POST') {
// Load Doctrine
$em = $this->getDoctrine()->getManager();
// Set Validator
$validator = $this->get('validator');
// Kitchen Details
$kitchen = new Kitchen();
$kitchen->setName($request->request->get('name'));
$kitchen->setDescription($request->request->get('description'));
$kitchen->setImage($request->files->get('main-image'));
// Sub Images
foreach ($request->files->get('sub-images') as $subimage)
{
$image = new KitchenImage();
$image->setImage($subimage);
$image->setKitchen($kitchen);
$image->upload();
$em->persist($image);
$kitchen->addImage($image);
}
// Validation
$errors = $validator->validate($kitchen);
if (count($errors) > 0) {
return new Response(print_r($errors, true));
}
else {
$kitchen->upload();
$em->persist($kitchen);
$em->flush();
return new Response('The kitchen is valid! Yes!');
}
}
return $this->render('PWDAdminBundle:Pages:add-kitchen.html.twig');
}
Kitchen Entity (Removed setters and getters for formatting):
/**
* #ORM\Entity
* #ORM\Table(name="kitchen")
*/
class Kitchen
{
/**
* #ORM\Id
* #ORM\Column(type="integer")
* #ORM\GeneratedValue(strategy="AUTO")
*/
protected $id;
/**
* #ORM\Column(type="string", length=100)
* #Assert\NotBlank()
*/
protected $name;
/**
* #ORM\Column(type="text")
* #Assert\NotBlank()
*/
protected $description;
/**
* #Assert\File(maxSize="6000000")
* #Assert\NotNull()
* #Assert\Image(
* minWidth = 800,
* maxWidth = 800,
* minHeight = 467,
* maxHeight = 467
* )
*/
protected $image;
/**
* #ORM\OneToMany(targetEntity="KitchenImage", mappedBy="kitchen")
*/
protected $images;
/**
* #ORM\Column(type="string", length=255, nullable=true)
*/
public $imagePath;
public function __construct()
{
$this->images = new ArrayCollection();
}
KitchenImage Entity:
class KitchenImage
{
/**
* #var integer
*
* #ORM\Column(name="id", type="integer")
* #ORM\Id
* #ORM\GeneratedValue(strategy="AUTO")
*/
protected $id;
/**
* #var string
*
* #Assert\File(maxSize="6000000")
* #Assert\NotNull()
* #Assert\Image(
* minWidth = 800,
* maxWidth = 800,
* minHeight = 467,
* maxHeight = 467
* )
*/
protected $image;
/**
* #ORM\ManyToOne(targetEntity="Kitchen", inversedBy="image")
* #ORM\JoinColumn(name="kitchen_id", referencedColumnName="id")
*/
protected $kitchen;
/**
* #ORM\Column(type="string", length=255, nullable=true)
*/
public $path;
I have tried the following on the Kitchen Entity:
/**
* #ORM\OneToMany(targetEntity="KitchenImage", mappedBy="kitchen")
* #Assert\All({
* #Assert\Valid
* })
*/
protected $images;
But I get the error message:
"The constraint Valid cannot be nested inside constraint Symfony\Component\Validator\Constraints\All.