DH takes his lunch to work, and we try to be cheap about it. These are some things he takes other than leftovers...
Chicken sandwiches- as in the cheapie chicken patties that are often on sale 4 in a package for a buck. Two packs of those plus a dollar bag of hamburger rolls from Kroger means 8 lunches for $3. I freeze them in baggies for him to nuke. I'd do the same with chicken fried steak patties if I could still get them around here.
Sausage biscuits, or sausage patties on little hard rolls- also made in advance and frozen two to a baggie.
Ravioli or chili in a can.
Frozen Michelina entrees- rarely more than $1- usually something like mac and cheese.
Sandwiches are doable- but he doesn't like to prepare his lunch before he leaves, he'd rather just grab something out of the freezer.
For snacks I buy big bags of pretzels or chips and baggy them.
Black beans and rice. If you buy the dried beans it takes a bit more time but you can make a big pot and freeze a portion of beans and rice together it a baggie. Put it in the fridge to thaw out overnight and send him off with a side tuperware of sour cream, cheese, chives, etc.
Completely not healthy, but El Monterey makes a selection of frozen burritos/chimichangas that are $3.38 for a pack of eight. Add some packets of taco sauce or some salsa and hey presto! Super cheap lunch.
Increase the volume when you cook, put the leftovers in freezer and microwave safe containers. Purchase family sized packs of meat, cook to your taste and then freeze for mix/match meals. Look in the luncheon meat/hotdog section for per-cooked seasoned chicken strips and such if you don't want to deal with the cooking.
Second rice and beans or pasta with veggies, you can add the pre-cooked meat to round out the meal.
for somewhat extreme, cook a whole chicken, turkey or roast. Dine on the "bird", carve and freeze the rest in single or double side servings. The single servings can be added to the lunch de jour. boild the cleaned carcass with some veggies and seasoning to make your own stock. Use the stock to make soup, stew or cook rice. Follow same process with roast.
Yogurt, puddings, and jellos make good desserts or snacks. Buy large bags of nuts, divide into sandwich bags for snacks. Same with cookies or crackers. String cheese also works well. SAMs or BJ's are great for these types of yummies.
Can you tell I brown bagged for awhile?
"Never do anything that you have to explain twice to the paramedics."
Courtesy my cousin Tim
You can nuke regular ramen in water. If you put the sauce in with the pasta before you put it in the fridge it doesn't get sticky and microwaves awesome. I love/loved those Michelina ones, cheeseburger Mac is amazing!!!!!
If you stick a sandwich in the fridge over night it stays pretty nicely for the next day too.