Esty I don't think we have to worry about canoncity. Remember the 'merry feast' Elrond has before the Council of Elrond. I don't think we are ever told what foods are there but with dwarves in company and we are told the food was all Frodo's hunger could desire...it surely would have been a mighty feast with I would imagine more than just vegetables.
So Rivendell at least had a variety of foods to offer all it's guests.