I make vegetable stock every week. Do you know what I use? All the scraps normally discarded: onion and garlic peels, the ends of carrots, celery, chard, and zucchini, herb stems, and other select vegetable peels. The cut-aways of most any veggies can be used but I focus on the aromatics (root vegetables like potatoes, parsnips, and turnips or squash peels are more pungent and can overwhelm the broth so I include just a few small pieces of those). I keep a container in my freezer where I collect the scraps and every weekend I pull it out, dump it into a big pot of water, and simmer. I've done this for years and it renders a deep, rich broth. If you eat seasonally, your broth will reflect that and be seasonal too! If I have meat bones (like turkey or chicken carcas, neckbones), I toss those in there as well. I prefer to make my broth unsalted so I have better control over salt content in the final dishes - braised meat and veggies, soups, risotto, beans, etc. If it's nearing the end of the week and I haven't used the broth for anything else I boil my pasta in it! I extract all the flavor and nutrients for myself before things end up in the compost!