You need to some dependency injection with the controller (assume it’s called RootController). Keep you nib file basic and create the controller programatically. In the interface add (with usual @synthesize and dealloc stuff):

@interface RootViewController : UITableViewController
{
UINavigationController *navigationController;
}
@property (nonatomic, retain) IBOutlet UINavigationController *navigationController;

And in the creation (e.g. the AppDelegate) add an extra line to manually set the navigation controller:

RootViewController* rootController =
[[RootViewController alloc] initWithNibName:@”RootViewController” bundle:nil];
navigationController =
[[UINavigationController alloc] initWithRootViewController:rootController];
rootController.navigationController = navigationController;

Then you can do the controller testing and mocking described so well above.