First of all, if you don't know the difference between stock and broth, go here. Now that you know there is a difference, ignore it. They're made the same way, so I will use them interchangeably. I don't think it really matters.
No matter how well you use your fabulous, organic, local vegetables, you will probably (inevitably) end up with some scraps. Now, these are fabulous to put into your compost or worm bin. But what does a smart environmentalist and foodie do? Save them and turn them into stock or broth. Seriously. The ends of carrots and parsnips that you won't put in your soup or stew, the ends of onions that you've cut up (take the skin off, but there's usually some viable onion under there), the hard core of cabbage, broccoli stems, the ends of celery, whatever. If it's a flavorful vegetable, throw it in there. Leafy greens are not a good option (they fall apart too easily), nor are potatoes (not flavorful enough). It's got to be something solid, which is why bright root vegetables work so well. Broccoli stems, too. I had some that I didn't want to use in broccoli-cheddar soup, because they were too woody. But that made them perfect for the stock.
I mentioned once before that Shane and I made chicken stock a while back, but it all got thrown out because we just never thought to use it. I'm trying to change that. Vegetable stock is even easier than a meat stock or broth, and just as tasty and nutritious.
When I say easy, I really do mean easy. I've had a bag full of scraps in the fridge for a few weeks now. Thanks to the freshness of the ingredients and the type (lots of winter/cold-hardy/root vegetables) they've been fine for a long period of time, long enough for me to collect a bunch of them. (Some people put them in the freezer if they know it'll take a while to build up enough.) The other night, I felt I had enough and that they would lose flavor/nutrients if I waited any longer, so I turned them into stock. How? Well. Here you go
Fill a pot with water, toss in the scraps, and cover. Bring to a boil, then reduce to a simmer for about an hour. I had it simmering while I did my workout. When you think it's gotten all of the nutrients out, strain it. The liquid should be either yellowish or greenish, depending on what you've used, and smell really decadent. That's it. Seriously. It's that easy. The scraps can go out to the compost, and the broth can either be frozen (some people use ice cube trays to make it super easy, then transfer the frozen cubes to either bags or jars for long-term storage) or into something delicious like this recipe. (It is so on my list of food to make soon!) If you're not going to freeze it, my suggestion would be to use meat stock or broth within a few days, and within a week for straight vegetable broth. I'm not a microbiologist or food safety expert, though, so those are just my estimates.
Meat stock is similar, except that you have meat bones in there as well as the vegetables. You can, of course, make broth or stock out of the good parts of meat and vegetables, but why waste them when using your leftovers and scraps makes them so tasty anyway? Stock was originally created as a way to get the most out of food, and it's no less necessary now than it used to be. If you roast a whole chicken, remove as much meat as possible, then save the carcass and turn it into a lovely broth. Don't worry that it won't taste "meaty" enough without the meat--the marrow will get boiled out and add flavor. Beef bones are another common item for stock, and I suppose we could use moose bones to make broth, but we tend to give them to the dog. She loves digging the marrow out of a nice big moose bone, and they can later be filled with things like peanut butter. Actually, that's her favorite toy. She doesn't play with us much, but give her some food to gnaw on and she's the happiest creature in the house. Since it's both frugal and a good use of something which would be wasted otherwise, Shane and I love it too.
Even when you think you're not wasting food, you probably are. Finding new ways to make the most out of what you have is the essence of frugality. When you can create something that's both good for you and for the environment out of that "waste", even better.