In other words a situation where you have an Orthodox Christian Greek speaking Anatolian state and a Muslim Turkish speaking Balkan state.
TTL Greece need not have all of Anatolia, but at minimum must hold the Aegean and Black Sea coastline, and preferably the Med coastline too. Bonus points for Constantinople, Thrace (East or otherwise), Crimea and Cyprus.
The Turkish state also need not be exclusively Balkan. Throw in Sicily, Southern Italy, Cyrenaica etc if you want/can. Preferably the capital is at Athens.
POD: Any time after 1025 (post Basil II).