Making vegetable (or chicken) broth (also called stock) is easy and very economical. I keep a large 5 qt. tub (it once held sherbet) in the freezer. Whenever I am prepping vegetables, anything in good condition (not moldy or too dirty) goes into the tub.
I was fortunate to attend a free sprouting workshop last week at the World Beat Center sponsored by Sky Mountain Institute. If you’re in the San Diego area, you definitely want to get on their mailing list, as they offer a free monthly workshop related to sustainable living. And, they’re really nice people.