1lbshrimp shells (heads included if you can find head on)
1bay leaf
1sprigfresh thyme
couple of black peppercorns
Instructions
Heat canola oil in a large pot over moderate heat. Cook the onions, celery, carrots, leeks, and garlic, stirring often, until they are soft but not brown, about 3 minutes.Add the shrimp shells , the bay leaf, thyme, peppercorns, and 3 quarts of water. Increase the heat to high and bring to a boil. Immediately reduce the heat to low and gently simmer, skimming any foam that rises to the surface, until the stock has reduced by half, about 2 hours.Strain through a fine sieve into a container with a cover. Allow the stock to cool. Cover and refrigerate, then skim off the fat. Freeze the stock in small batches to use later.