You don't mention any restrictions, so here it goes:
I make a crock pot of stew with 1 steak, 1 clove garlic, 1 large potato, 1 tomato, 3-4 carrots, 1 stalk of celery, 1/2 onion (chopped), 1/2 zucchini, 1 small can tomato sauce, chicken/veggie/beef stock, and you can add a hand full of cooked pasta if you like.
I usually have everything except the potato cut and if I am in a hurry, I place the steak in the pot to brown, remove it and set it aside, then toss the veggies in the pot until they are browned, and then add the stock, sauce, and steak. If it is not enough, add grilled cheese sandwiches.
A precooked chicken is pretty inexpensive. You can add veggies and rice or potatoes.
Boil the left over chicken and carcass to make soup the next day. Serve soup and simple sandwiches.
A quiche would be good for breakfast.
If you have a safeway/vons, you can get a variety of premade sandwiches from their deli. The 8th or 10th one should be fee with your Vons club card. It is here in Vegas. Add a potato salad. Trader Joes has the best potato salad.
Oh, cut the sandwiches in 3rds or 4ths.
Have a pizza/pasta/salad night. You can make the pasta and salad and order the pizza.
Beans, tacos, burritos, tostadas. Set everything out so they can build their own. You can buy the rice at most restaurants or a Latin market for very cheap.
Baked chicken wings. You can spread them on a cookie sheet and season.
That's all I've got.