Peanut butter or Neutella on any kind of bread (bagels, tortillas, pita, etc...) Tuna fish sandwiches on bagels, hummus(instant kind) with carrots, cucumbers, and pita or bagel chips. Individaully wrapped cheese sticks last pretty well too. If you're willing to heat water, try curry powder mixed with instant potatoes and served as a sandwich on pita bread (should be chapati but most people don't have access to this Indian bread).