Lunch or Breakfast Spots for Group Meetings

I am looking for a place downtown (Loop or River North) to hold occasional breakfast or lunch meetings for a group of around 15-25, usually involving a speaker presentation (think Rotary, etc.). In the past we have held meetings at the Union League Club or Chicago Yacht Club but the cost can get very steep. Does anyone know of venues where we could reserve a private room and, preferably, people could order off the menu and pay individually OR offers a modest prix-fixe meal for fewer than 25 people?

Thanks in advance for any suggestions.
Katie

Not exactly north, but not too south: Eleven City Diner has a private dining room, http://www.elevencitydiner.com/events-and-parties. They open at 8AM (which may be too late, I realize).

East Bank Club is a possible option. I've hosted meetings there and they're pretty reasonable.

East Bank Club
500 North Kingsbury Street
Chicago, IL 60654-5799
(312) 527-5800

How about the back room @ Prairie Fire?