I don't think they'll be getting too many more kids with this policy! What a pain in the arse!
I'd go hot for lunch. Make a large tuna pasta bake/macaroni cheese/risotto/Bolognese etc and then reheat a portion in the morning and put in a thermos. I'd probably do one on Sunday night for Monday/Tuesday and then another on Tuesday night for Wednesday/Thursday.
For dinner a selection of picky bits that cover all your main food groups:
Protein: chicken or any meat (again can cook in advance and put in the fridge), ham, sausages, tuna, salmon, omelette, boiled egg, houmous
Dairy: pieces of cheese, yoghurt
Veg: carrot sticks, cucumber, pepper, tomatoes, corn on the cob, sweetcorn, celery
Fruit: melon, mango, kiwi, grapes, banana, satsumas, peaches, blueberries, blackberries all travel well. I find raspberries and strawberries are a bit soft and apple goes brown.
Carb: Bread, bagel, pitta, wrap, breadsticks, oatcakes, crackers, pasta salad, slice of pizza.