Yes there are a few, one of our favorites is at the base of the hill where you turn up to go to the Conrad.(Can't remember the name, we were there 2 years ago) Walk down from the conrad, go straight across the main street like you are going to the ferry service area, go left about a 100 yds or so to a building that fronts the water, it is multi level and has a floor for sea food and a seperate floor for more traditional foods, sea food is expensive, the traditional food is very reasonalble. The entrance is on the side of the building facing the bus and ferry terminal. Every time we were in the place, it was packed, didn't see tourist one there when we were there.
As a side note, you can take the water ferries to just about anywhere and they are very cheap and a nice way to see the sights, take the one across the Bosphorus to Asia and back again.
good luck^^