Based on a pull request by lukasluecke
I recommend that you don't. However:
composer require madforit/easyadmin-embed-bundle
Change your CRUD controller to extend Madforit\EasyAdminEmbedBundle\Controller\AbstractCrudController
class MyCrudController extends \Madforit\EasyAdminEmbedBundle\Controller\AbstractCrudController {
public function configureFields(string $pageName): iterable {
// Unfortunately you have to specify the template here
yield EmbedField::new('relation_field')->setTemplatePath('@EasyAdminEmbed/crud/field/embed.html.twig')
}
}