HomePage.ss

<% loop $Menu(1) %>
	$RenderLayout
<% end_loop %>

Page.php

<?php

class Page extends SiteTree {
	
	/**
	 * Mimics the bevahiour of $Layout in templates
	 * @return HTMLText
	 */
	public function RenderLayout() {
		$template = $this->findLayout();

		$subtemplateViewer = new SSViewer($template);
		$subtemplateViewer->includeRequirements(false);
		return $subtemplateViewer->process($this);
	}
	
	/**
	 * Find the appropriate "$Layout" template for this class
	 * @throws Exception
	 * @return string
	 */
	protected function findLayout() {
		$theme = Config::inst()->get('SSViewer', 'theme');

		$templateList = array();
		$parentClass = $this->class;
		while($parentClass !== 'SiteTree') {
			$templateList[] = $parentClass;
			$parentClass = get_parent_class($parentClass);
		}

		$templates = SS_TemplateLoader::instance()->findTemplates($templateList, $theme);
		if( ! isset($templates['Layout'])) {
			throw new Exception('No layout found for class: ' . get_class($this));
		}
		
		return $templates['Layout'];
	}
	
}

class Page_Controller extends ContentController {
	
}