the last time was when Comey appointed U.S. Attorney Patrick Fitzgerald as a special counsel when he was Deputy Attorney General. The dems are caught between a rock and a hard place if they want the new AG to fire Durham. Remember, we've all been told that terminating a special counsel = obstruction and therefore the POTUS must be impeached.
https://www.lawfareblog.com/statutory-authority-barrs-appointment-durham-special-counsel