Tuna pasta salad.
Though I work a student job its a bit more lenient with breaks thing is I do not like spending money on food around me (most tend to be fast food ish place) trying to cut that out. That being said this past month I made some tuna pasta and sometimes just added chopped celery, tomatoes. Thank god it's a school job it's very easy for me to get condiments around work.
I also simply used some good old oatmeal and took it to work, about two packs of quaker oatmeal, with a bottle of milk for about 99 cents lead to a cheap filling lunch. Then again I really really love oatmeal and my friends call me old for eating it so much
oh if you do like oatmeal you can put raspberries, or get a bannana and break it up or strawberries! Those three things taste so delicious with oatmeal!