Gavra
You do realize that in those days they learned baal peh (I think even once the gemara was put down in writing the preferred method was still baall peh) so it was possible to do some cooking while reciting mishnayos baal peh or thinking in learning.
Much harder today when we learn from sefarim and most people don’t know much of anything baal peh. Additionally we aren’t the amoraim and if we tried to learn and cook the likelihood of the food getting burned or ingredients left out. ..is high. Although I have listened to shiurim (nothing too involving) while doing other things so it is possible to do light learning while doing something else as lkng as the something else doesn’t require too much focus.