On the weekend make a large pot of soup. Place single servings into zip lock bags and store a couple in the fridge, rest in freezer. Then when you want a fast meal, nuke it (or make a could soup) and carry the cup to class. If you are stuck on campus, talk to your department or a professor you know well. If you explain the situation they may find a micro wave in one of the teachers lounges you can use.

Quiches are another thing that freezes well in individual portions. Just take out a portion and carry it with you. It will keep safly.

With store bought mayo, an egg or tuna salad will keep in a bag or lunch box untuil lunch. Just be sure to clean out the container when you get home or your papers may smell funky in a week.

I foudn one of the best lunches to take to school was a wrap. I made a cheeseburger and put it in a napa cabbage leaf. Then I sealed it in a rubbermade container. By the time lunch rolled around the juices from the burger had seeped into the cabbage leaf just enough to hold it in place, while still being crunchy. It was great.

If you can stand a smaller lunch until you get more time to eat, have a snack. Take raw veggies to mucnh, or celery with cheese inside. A ziplock bag can work as a glove, and you can take a steak or chicken breast, eating carefully using the glove. Making sure to have a snack before and after class can help without suddenly starving to death midday and make a liter snack all you need.