Yes, doping, blah blah we get it. But the logistics of TdF is insane. With a new city every day, things need to move fast and preparations start early. For instance Uno-X team has a small trailer with 800 kgs of ice they travel around with, after having trouble sourcing enough ice in the small villages they stay at.
Actually having your own chef source stuff is one way to avoid accidental doping scandals.
I've read the Velochef book and like the recipes there. One thing I've never appreciated before is how hard it is to actually get this amount of calories down. Especially since much of it must be consumed on the bike so needs to be easy to transport/store/eat on the fly. And eating while working out can be tough on the stomach. EDB finally got his break through when they managed to nail a nutrition he didn't get cramps from eating.