buy the cheapest roast (pork or beef) that is in the store, season with salt & pepper or steak seasoning (yum) and throw it in the crockpot with a little bit of water at the bottom. Cook it all day (or night) long and savor the results of time. add veggies/potatoes on bottom if you want.
leftover roast:
~bbq sandwiches on toasted buns (get those from the day-old bread store)
~stroganoff (really cheap and super easy)
~use in fajitas/burritos/quesadillas, etc. if you're not going to eat them in the next few days, make them up and freeze them for a quick meal later
~trash soup/stew - make a soup with all the leftover veggies from the week, a can of potatoes, leftover meat. whip up some biscuits or have the kids help me homemade rolls or garlic bread/breadsticks to go with.
other ideas:
~eggs anything. as long as you don't have to buy egg substitute, meals with eggs will be cheap cheap. hit sites like bettycrocker.com, kraftfoods.com, allrecipes.com, bisquick.com for quick recipes.
~you can dress up a box of mac/cheese by adding veggies, meat leftovers, etc.
~put leftovers in a muffin tin (with liners in each cup). freeze as you fill them and put frozen cups in a freezer bag to store. have a leftover smorgasboard for dinner one night - bust out all the muffin cups and stick them back into the tin, heat through in the oven, and let the kids go wild picking from a whole buffet. Add a salad (fruit or green) and some garlic bread and you're golden.
*have popcorn (kernal vs microwave kind will be WAY cheaper and last you far longer), cookies, etc on hand for snacks so you can get by with less for dinner. You may gain a pound, but you'll get through the hard time with a full stomach.