It is one thing to cook a large amount of food specifically for the leftovers, but it is something else to plan a series of cascading meals built around the idea of using leftovers from one meal to build another very different meal.
Look at the effort to use up turkey leftovers. You have the turkey, then turkey sandwiches, then turkey hash, and finally turkey soup. There may be even more steps in there, but you get the idea.
We are trying to see how long it can go on for. We used a large flatiron steak for fajitas, and used it again for steak sandwiches. We also made Broccoli Beef from it and plain rice, then used the extra rice in Fried Rice and some teriyaki Chicken, which is going into potstickers with the fried rice as a side dish.
This certainly makes the most sense for things that take a lot of energy to make in the first place, but that also store well when cooked. Up here in Denver rice takes about 23 minutes to cook, which isn't too bad, but I can make extra and refrigerate it for a few days and do all kinds of things with it. Rice also freezes very well.
Beans take much longer then rice and if you are careful not to break them up too much they store in the fridge and freezer quite well. And if it didn't store too well you can always make refried beans out of it.
It allows you to spend more time on the main dish with less worry about the side dish.
You can do it the other way too, like with the turkey. Once you have a main dish ready to go you can spend your time on an extra special side dish. Kinda like putting an okay piece of art in a really nice frame.
Then there are things like Italian sausage. I really like hot Italian sausage in spaghetti sauce , and lasagna and in a few other applications. And we always use it cooked and crumbled. So rather then keeping the raw form frozen in a big lump, which needs to be defrosted. It is easier to cook and drain a big bulk package of it and then bag, tag and freeze and just pull out a handful as needed.
Share your ideas on how your cascade your leftovers to different meals.