Not the parent, but I work from home and yes, very often it's a sandwich for lunch. Or more than one sandwich throughout the day, since with complete schedule freedom you are not tied to conventions like lunch hours.
Sandwiches can be great :) I prefer only whole-wheat or other whole-grain breads (for both sandwiches as well as other uses), and healthy sandwich ingredients, although I'm not rigid about it - I will go for less healthy ingredients sometimes, or if I cannot avoid them, on occasion. (The healthy ones tend to taste better too, anyway.)
I cook a warm meal for dinner. Works for me.