We packed all of our lunches last time. We have a small (can hold 12 soda cans) soft-sided cooler and we just put it in the basket under the stroller.
We put in a cold-pack and we packed pb&j, ham and cheese and tuna sandwiches--alternating days. We packed applesauce, and fruit cups, soda and chips. One day we packed ritz crackers, cheese, grapes and apples--that was a very popular lunch!
Since we spent $0 on lunch we did not hesitate to purchase ice cream or other snacks that we normally would not spend the money on.
In fact, my family preferred packing their lunches. My son is an early lunch eater, my daughter is a late lunch eater and my husband is a BIG lunch eater.