It's now hard to find a genuinely kosher restaurant in Tel-Aviv. The majority of restaurants me and wife looked into served unkosher meat or meat with milk. It got to a point that we had to ask if the meat was kosher and they would shrug...sure enough the first night we arrived, there were no places available and we had to eat vegetarian (as we usually do in the United States because there are barely any kosher places here that are halfway decent or healthy).
However everywhere we were in Israel we always checked to see if the place was kosher. Back in the day before they allowed non Jewish Russians (and the Israeli government call them Jewish), there was no issue if a place was kosher.
However, in Tel-Aviv, it's really bad..the vast majority of places are unkosher. In Jerusalem and Ashdod, so far, it's pretty good. The majority of places in those cities are..but there a good number of nonkosher restaurants there as well.