Making your own vegetable stock is easy and costs almost nothing. Use the trimmings from your vegetables, including onion skins, garlic skins, herb stems, potato and carrot peelings--just about anything in your kitchen except sulfurous vegetables such as broccoli, cauliflower and cabbage. Also toss in anything in your fridge that looks like it's not so happy any more. This recipe uses a reduction method that produces a very rich stock, which increases the cooking time. You can do this in a third of the time by doing only 1 reduction, which takes about 45 minutes to an hour cooking time. But I highly recommend reducing 3 times.