Free Vegetable Stock
from Christin Butler, who finally gave me the kick in the pants I
needed to do what I've understood I should do for decades. This is a
major saving, because one good bouillon cube costs about 40 cents.
This is my method:
1. I keep the crappy parts of vegetables that I don't use while I'm cooking such as: carrot root ends, carrot greens (very nutritious but not so pleasant to actually eat), onion skins*, celery leaves, pepper tops, mushroom stems, and whatever else, and put them in a quart-sized freezer bag which I just always keep in the freezer. Don't keep stuff like broccoli and strong greens, since the flavors are too powerful. I only add a small amount of tomato scraps, because it can also overpower the broth and make it too sweet.
2. When the bag is full, I add the contents of the bag, plus a quart and half or so of water, a little salt, some peppercorns, a bay leaf, whatever not so fresh anymore herbs I may have on hand, and a piece or two of kombu kelp (which I'm only guessing you also have on hand because I saw, but didn't read, your recipe for miso soup) to a stock pot.
3. Bring it to a boil, turn the heat down to a low simmer, then let it go for a while-- maybe 45 minutes to an hour. Then I just strain out the liquid and freeze it in individual containers. Compost the leftover veggies as usual.
Hope you or someone else finds this useful!