Restaurant in Union Market/CH with Private Room

I’m getting married this year and we are looking for a rehearsal dinner venue that has a private room. We were hoping to do Pastis in Union Market but they do not have a private room and we want something more private. We also like the Duck and the Peach but they also do not have a private room. Do you have recommendations for restaurants in Union Market or Eastern Market/Capitol Hill that have a private room for ~30 people?