Elesh Norn, Mother of Machine's second ability is not working properly with permanents triggering cards in the graveyard. The ability only affects permanents, not permanent cards. However, when discarding Ovalchase Daredevil to The Underworld Cookbook, the food token entering the battlefield does not trigger Ovalchase Daredevil's ability to return to hand. I have heard from other sources that the same thing happens when playing a land with Bloodghast in your graveyard (Bloodghast's ability does not trigger, but should). For reference to see this issue in action, see Modern League #7132, Match #257317850, Game #832402182. My MTGO username is JangoUnFettered and in this game on my turn 7 you can this this interaction and bug take place.