We have visited Myrtia during our visit in Athens for a friend's bachelor. Despite that we lived in Athens for 5+ years we didn't spotted this hidden place and went after my brother suggested visiting.
The place is like the most typical Greek taverns but the portion are extremely big and the overall conclusion value for money. You should try the Pork Chop.
You must try the 'on the house' donuts with chocolate at the end.