Instructions

1. Give the onions, carrots, and celery stalks a rough chop. You don't even need to peel them first unless you really want to. (Some people even advocate leaving on the onion skins!)
2. Throw all the vegetables in a pot big enough to hold them plus a few extra inches of water. Add fresh thyme sprigs, 1 bay leaf, 1 small bunch fresh parsley, and 1 teaspoon whole black peppercorns.
3. Cover the vegetables with enough water that you can easily stir them in the pot. Less water means that your stock will be more concentrated; more water makes a lighter-flavored stock. Set the pot over medium-high heat and bring it to just under a boil. Once you start to see some bubbling around the edges of the pot and a few wisps of steam on the surface, turn the heat down to medium-low.
4. This isn't an exact science, but simmering for 1 hour is generally enough time to infuse the water with vegetable goodness. If you need to take it off the heat a little early or don't get to it until a little later, it will be fine. Give it a stir every now and again to circulate the vegetables.
5. Take the pot off the stove and remove all the vegetables with a slotted spoon. Set a colander or strainer over a big bowl and line it with cheesecloth or coffee filters. Pour the stock through. If not using immediately, divide the stock into storage containers, cool completely, and then freeze.