App::missing(function($exception)
{
    return Response::view('errors.404', array('error'=>$exception), 404);
});

//I know this code doesn't work, I've just wanted to show the claim
App::missing('HomeController@error');
App::error('HomeController@error');
// or ...

public function error(Closure $callback)
{
    $this['exception']->error($callback);
}

App::missing(function($e){
    // Use the model here you want
    $var = 'SomeValue' from model
    return Response::view('errors.404', array('error'=> $e, 'another' => $var));
});

App::missing(function($exception)
{
    return App::make('HomeController')->error($exception);
});