Register a block pattern using PHP. Fits into the Theme structure of https://github.com/SayHelloGmbH/hello-roots/

group-with-media-text.php

<!-- wp:group {"backgroundColor":"secondary","textColor":"primary","layout":{"inherit":true}} -->
<div class="wp-block-group has-primary-color has-secondary-background-color has-text-color has-background">
	<!-- wp:media-text -->
	<div class="wp-block-media-text alignwide is-stacked-on-mobile">
		<figure class="wp-block-media-text__media"></figure>
		<div class="wp-block-media-text__content">
			<!-- wp:paragraph -->
			<p>Lorem ipsum dolor sit amet consectetur adipisicing elit. Officia magni, aut esse aliquam omnis voluptate placeat nemo dolorem totam beatae, ipsa atque veritatis impedit tempora quaerat, perferendis accusamus! Ab, ipsam.</p>
			<!-- /wp:paragraph -->
		</div>
	</div>
	<!-- /wp:media-text -->
</div>
<!-- /wp:group -->

GroupWithMediaText.php

<?php

namespace SayHello\Theme\Pattern;

/**
 * Manage single block pattern
 *
 * @author Say Hello GmbH <hello@sayhello.ch>
 */
class GroupWithMediaText
{

	public function run()
	{
		add_filter('init', [$this, 'register']);
	}

	public function register()
	{
		ob_start();
		get_template_part('partials/patterns/group-with-media-text');
		$content = ob_get_contents();
		ob_end_clean();

		register_block_pattern(
			'sht/group-with-media-text',
			[
				'title' => __('Group with media and text', 'sha'),
				'categories' => ['text'],
				'content' => $content,
			]
		);
	}
}