I have been on easyJet flights from London Luton to Tel Aviv where Kosher food was available to purchase, this is not advertised on the menu or as far as I could tell online. Which routes does easyJet offer Kosher food?
I tweeted easyjet about it and they replied in a private message:
Kosher food and kosher milk for coffee are offered on our Tel Aviv route. This food is priced in line with the other products available on board.
Please ask one of our cabin crew to check the options available. :)
So it seems the Tel Aviv routes (there is a few of them and I assume they meant not only one) are the only ones they carry kosher food on. Given the response not by tweet but by message they also explicitly choose not to advertise this option, as you state in a comment.