I've been a nanny for some years now and here are the things that my previous charges took in as packed lunches:
Child 1 (age 5) - ham sandwich with butter in brown bread, breadstix with fruit puree to dip, yoghurt, carton apple juice, banana, babybel
Child 2 (age 4) - marmite and cream cheese sandwich in brown bread, breadstix with fruit puree or soft cheese to dip, apple or banana, carton apple juice, occasionally pot of cherry tom's
These 2 particular children NEVER varied in their lunchboxes. (I didn't make them btw or would have added more veg).
Child 3 - ham on white roll with butter, 1/2 cucumber, 2 individual cheeses, grapes, water in reusable bottle
Also a never-varier. Also made by Mum in mornings.
Child 4 - 1) sandwich with either tuna & sweetcorn, egg mayonnaise, or peppers & hummus; or
Pasta with any of the above fillings or
Soup (leek & potato, sweet pot & chorizo) or
Pizza muffins - 1/2 muffin, pizza sauce, cheese, variety of toppings or
Cous cous, rice, or noodles with various bulk veg/sauce
2)babybel/cheese string,
3)yoghurt
4)banana/grapes/apple/strawberries/kiwi/melon (whatever was in season/we had in at the time)
5) carrot batons, baby sweetcorns, steamed green beans, steamed broccoli
This particular child was a very good eater and as his 'treat' always had a thermos of hot chocolate for lunch 