Great food and cocktails for 12 pp
Marc Forgione, for the food moreso than the cocktails, though they do have a composed cocktail list. Also, if you wanted to go anywhere afterwards for cocktails, Ward III is right down the block and Silver Lining is also nearby.
I assume that WD-50 would be too risky for a group of 12, but if they are all adventurous it has historically had excellent cocktails to go along with their food. Have not been since they redid their entire menu, including cocktails, but I wouldn't imagine the quality has fallen.