Boarded a flight today, everything seemed fine. About an hour into the flight, FA starts handing out snacks, and then informs everyone in the front cabin that the ovens are broken, and that they only found out 15 minutes before the flight. Offered choice of cold sandwiches (either vegetarian or mystery meat). Glad I ate in the lounge beforehand. Really unfortunate that they didn't mention it prior to boarding, so that people could buy their own hot meals beforehand.