I don't think the Route::controller works with Lumen.

You could just make the rest routes yourself,

In you routes.php file

 $app->get('foo', 'fooController@index');
 $app->get('foo/{id}', 'fooController@show');
 $app->post('foo', 'fooController@store');
 $app->put('foo/{id}', 'fooController@update');
 $app->delete('foo/{id}', 'fooController@destroy');

// the controllers will need a full class path

It wouldn't take much to make this a small function if you have multiple routes. The you could do something like,

makeControllerRoute('/foo', 'App\Http\Controllers\fooController');

And since you say works "out of the box".. I'm going to add in a reminder about if you want to use the facades you will need to enable them in the app.php file along with the .env load config support.

Dotenv::load(__DIR__.'/../');

$app->withFacades();
 
$app->withEloquent();

Hope that helps.