Ingredients

　　3 onions, chopped

　　3 tablespoons unsalted butter

　　the white and pale green part of 2 leeks, washed well and chopped

　　2 carrots, chopped

　　2 ribs of celery, chopped

　　1/4 pound mushrooms (preferably ones with opened caps), chopped

　　1 cup potato peelings

　　12 1/3 cups cold water

　　1/4 cup lentils

　　6 unpeeled garlic cloves

　　1/2 teaspoon black peppercorns

　　1/2 teaspoon dried thyme, crumbled

　　1 bay leaf

　　12 long parsley sprigs

　　1 teaspoon salt

　　In a stockpot or kettle cook the onions in the butter over moderate heat, stirring, until they are golden, add the leeks, the carrots, the celery, the mushrooms, the potato peelings, and 1/3 cup of the water, and simmer the mixture, covered, stirring occasionally, for 5 minutes. Add the remaining water, the lentils, the garlic, the peppercorns, the thyme, the bay leaf, the parsley,and the salt, bring the mixture to a boil, and simmer it, uncovered, for 2 hours. Strain the stock through a fine sieve into a bowl and let it cool. Chill the stock and remove the fat.