Earlier recess appointments were made when congress was in actually in recess. Obama did it while congress was not in recess. In other words he appointed who he wanted outside the law and through down a challenge to the other branches to do something about it. If he wins this without repercussions, he is truly a dictator.
If I recall correctly “recess” appointments were previously made while Congress was actually in recess, and were subject to apporval when they reconviened.
Otherwise just wait for every recess and appoint who you want.