Sage 10 - how to return blade templates from setup.php for custom shortcodes?

In Sage 10 Roots\view is responsible for rendering:

    view('subfolder/some-template-file', [ // no file extension (`blade.php`)
        'some_parameter' => 'test123',
    ])->render();

The path to the template file is relative to the resources/views directory of the Sage 10 theme directory.
The constructor results in a View object whose render method returns the rendered template.

Tip: Add use function Roots\view; at the beginning of the PHP file so you can just use view(...) instead explicitly typing out the Roots namespace.