My son is eating lunch at school for the first time this year and we too have always done a lot of hot lunches at home. PB & J is out for us too. Does she like lunch meat? They are the only sandwiches my son will eat so I have thought of ways to mix it up a bit and try to make the other lunch items more fun.
For the sandwich i sometimes put it on regular bread and use a large cookie cutter to shape it or make it on a small sandwich kaiser roll (the ones in the Dominicks bakery section are perfect for young kids).
My son really wants "Lunchables" to make the cracker sandwich but instead of buying them I make them. I slice the cheese and make a shape with a small cookie cutter and do the same for salami or summer sausage, and put some crackers in.
I started to make blueberry and bannana mini muffins and give him 2 in his lunch for a special treat.
I make a large bowl of sugar free jello or pudding and scoop a serving into a small tuperware container as a treat (it is cheaper than buying the small individual serving cups).
I always let him pick a type of fruit and some chips.
I haven't done it yet but I have heard if you have a small thermos you can put mac n cheese and soup in it and it will be warm when they eat it at lunch.
Since I don't feel like I have many options for my picky eater I try add little extras. I bought some different birthday napkins and a sheet of matching stickers (batman, spiderman etc.) and make a different theme each day. I put a napkin and a if I have any zip lock sandwich bags I put a sticker on it.
I hope some of these ideas I have found will also work for you!!