<?php

$metabox = new Custom_Post_Type();
$metabox->post_type_name = 'page';
$metabox->add_meta_box('Layout Options', array('Hide Page Title' => array('type' => 'checkbox', 'data' => array('checked' => 'on')), 'Related Recipe' => 'custom-post-type-select'), 'side', 'low', array('custom-post-type-select' => array('Related Recipe' => array('post_type' => 'wpmon_recipe', 'default_label' => 'Default', 'args' => array()))), '', false);
<?php

// Initialize Post Type
$my_recipe = new Custom_Post_Type('Recipe', 'wpmon', array('menu_position' => '25', 'menu_icon' => 'dashicons-images-alt', 'has_archive' => 'false', 'supports' => array('title', 'editor', 'thumbnail')), array('menu_name' => 'Recipes'), 'Recipe', true);
// Add Custom Taxonomy
$my_recipe->add_taxonomy('meal');
$my_recipe->add_taxonomy('cuisine');
// Add Metaboxes
$my_recipe->add_meta_box('Example Options', array('instructions' => 'html-block', 'Select Some Things' => 'select', 'Meal' => 'category-multi-select', 'Test Question IDs' => 'hidden', 'More Information Link' => 'content-url', 'Date' => 'date', 'Time' => 'time'), 'normal', 'default', array('select_options' => array('Select Some Things' => array('My Option 1' => 'option-1', 'My Option 2' => 'option-2', 'My Option 3' => 'option-3', 'My Option 4' => 'option-4')), 'category_multi_select' => array('Meal' => array('post_type' => 'wpmon_recipe', 'taxonomy' => 'wpmon_meals')), 'html_block' => array('instructions' => array('heading' => 'Instructions', 'html' => '[my-shortcode]'))), '', false);
function example_shortcode_function()
{
    $output = '<p>Here, you can place HTML content to give your users some good direction.</p>';
    $output .= '<p>You can even use shortcodes!!</p>';
    return $output;
}
add_shortcode('my-shortcode', 'example_shortcode_function');