On the other hand sandwiches could be various depending on what you put on them, don’t you think? If you have the possibility to heat food in the forest, you can use leftovers from the day before. Some leftovers you can probably eat cold if you are hungry enough.
One could wish that there were caterers who could deliver fresh food in the forest two times a day. I guess there are, but the costs for that … Probably better, and cheaper, to use your imagination.