Start Session into Laravel with user id from another framework

I pass the user id from another framework to Laravel.

How can i start a Laravel 5.1 Session with this user id?

So the user will be logged in into Laravel coming from another framework login.

My method to receive the user id :

public function user( $user_id )
{
      Auth::loginUsingId($user_id);
      //echo Auth::check($user_id);
      return view('mymethod.index');
}

I found this way below, but does not know if Session::has('user') will work after this : $request->session()->put('key', 'value');

via Chebli Mohamed