Hacı Abdullah is serving traditional Ottoman cuisine since 1888 and claiming to be the oldest licenced restaurant of Istanbul. All food are delicious but especially famous for its compote. You'll notice glass jars filled with fruit compotes at the entrance.
Alcoholic drinks are not served here so I advice you to enjoy a lunch. Prices are over average (not much) when compared with similar restaurants but you won't regret!
You'll notice Ağa Mosque on your right, turn to this street and you'll notice on your left.