My DD is going into 6th grade. She is a very picky eater.
Since she is getting a bit older, she will occasionally pack her own lunch (fairly healthy I might add - with enough "something fun" to keep it interesting for her.) When she packs her own lunch - she will literally count out how many carrots are in 2 servings, etc. She will try to get at least 1 fruit and 1 veggie when she packs her lunch.
Some of her favorite non-sandwich things are Ramen noodles, soft tortilla shells stuffed with lettuce and shredded cheese, cold chicken cut up - with toothpicks in it, cheese and crackers or chicken noodle soup. For sandwiches, she sometimes likes peanut butter and bananas.
The wide-neck thermos is a wonderful thing!
I won't have to deal with this for a couple of more weeks, school doesn't start here for 2 more weeks. And, since she is in middle school this year, they now have a salad bar too!