Sounds like you do really important work. Feeding many with very little is a challenge. The key here is combining fiber (maximize it) to create a filling dish and to add protein (even a little bit) to provide "stick to the ribs" satisfaction.
Good foods to use are:
-brown rice (great in a stir fry)
- garbanzo beans (great in a salad or stew)
-fortified noodles
-black beans
-tuna
-eggs
So, try stir fries, curry with rice, black bean tostadas, fish cakes, vegetable quiche, frittata