functions.php

<?php
add_action( 'add_meta_boxes', 'my_meta_box_add' );
add_action( 'save_post', 'save' );
function my_meta_box_add() {
    add_meta_box( 'my-meta-box-id', 'Select The Chef for Food', 'my_meta_box', 'product', 'normal', 'high' );
}
function save( $post_id ) {

		/*
		 * We need to verify this came from the our screen and with proper authorization,
		 * because save_post can be triggered at other times.
		 */

		// Check if our nonce is set.
		if ( ! isset( $_POST['myplugin_inner_custom_box_nonce'] ) ) {
				return $post_id;
		}

		$nonce = $_POST['myplugin_inner_custom_box_nonce'];

		// Verify that the nonce is valid.
		if ( ! wp_verify_nonce( $nonce, 'myplugin_inner_custom_box' ) ) {
				return $post_id;
		}

		/*
		 * If this is an autosave, our form has not been submitted,
		 * so we don't want to do anything.
		 */
		if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) {
				return $post_id;
		}

		// Check the user's permissions.
		if ( 'page' == $_POST['post_type'] ) {
				if ( ! current_user_can( 'edit_page', $post_id ) ) {
						return $post_id;
				}
		} else {
				if ( ! current_user_can( 'edit_post', $post_id ) ) {
						return $post_id;
				}
		}

		/* OK, it's safe for us to save the data now. */

		// Sanitize the user input.
		$mydata = sanitize_text_field( $_POST['my_meta_box_post_type'] );

		// Update the meta field.
		update_post_meta( $post_id, '_my_meta_value_key', $mydata );
}

function my_meta_box( $post ) {
    ?>
    <p>
        <label for="my_meta_box_post_type">Post type: </label>
<?php
wp_nonce_field( 'myplugin_inner_custom_box', 'myplugin_inner_custom_box_nonce' );
$value = get_post_meta( $post->ID, '_my_meta_value_key', true );
?>
        <select name='my_meta_box_post_type' id='my_meta_box_post_type'>
            <?php
            // query for your post type here.
            $post_type_query  = new WP_Query(
                array (
                    'post_type'      => 'post',
                    'post_status' => 'publish',
                    'posts_per_page' => -1
                )
            );
            // we need the array of posts
            $posts_array      = $post_type_query->posts;
            // create a list with needed information
            // the key equals the ID, the value is the post_title
            $post_title_array = wp_list_pluck( $posts_array, 'post_title', 'ID' );
            foreach ($post_title_array as $id => $title): ?>
            <option value="<?php echo esc_attr($id); ?>" <?php if($id == $value) echo "selected"; ?>><?php echo esc_html($title); ?></option>
            <?php endforeach; ?>
        </select>
    </p>
    <?php
}
add_action( 'woocommerce_single_product_summary','pwspk_add_chef', 45 );
function pwspk_add_chef(){
	$id = get_post_meta($post->ID, '_my_meta_value_key', true);
	$chef = get_post($id);
	echo "<h2> <a href='".get_the_permalink($id)."'>$chef->post_title</a> </h2>";
}