Do you ever do snacky meals for lunch?   We do.  Here are few that are popular with my kids.

Tortilla chips and melted cheese.   I also offer cut up chunks of chicken, sour cream, and salsa to dip the chips in.  Also some veggies if they're in the mood..cut up tomatoes or onions (they don't often take advantage of those though)

We also sometimes do fruits.   Apples with peanut butter to dip, strawberries, grapes, bananas or whatever we have for fruit.  I will also offer cheese and crackers on the side or popcorn.   My kids really love this.

Any other ideas to share?