I’ve gone commando, everyone does it. You don’t want to cook in hot, sweaty pants. It’s a chef thing.
As the immortal Inigo Montoya says in The Princess Bride: “You keep using that word. I do not think it means what you think it means.”
Ramsay seems to be describing peeling off those delightful checked chef’s pants and cooking in his underwear on those nights that he can’t stand the heat, but doesn’t want to get out of the kitchen.
Either way, I’m not sure I want to think about anyone who has contact with my food leaving part of their attire at home.