Lunch reservation for 25?

My work is looking for a place we can have our staff holiday celebration, that will take an afternoon reservation for a group of about 25 people. Ideally we would love place that we can mingle and chat with one another, we've done a game room type bar in the past. Hoping for something downtown or in Northwest or inner east side. And of course we will need to accommodate a variety of diets like gluten-free and vegan. Any ideas?