BASIC VEGETABLE STOCK MAKES 2 QUARTS 1 ounce (4 packets; about 3 tablespoons) unflavored gelatin 2 large onions, roughly chopped 2 large carrots, peeled and roughly chopped 4 stalks celery, roughly chopped 1 large leek, trimmed 8 ounces mushroom stems and scraps and/or whole mushrooms 2 Granny Smith apples, quartered 2 bay leaves 2 teaspoons whole black peppercorns 1 teaspoon fennel seeds 1 teaspoon coriander seeds 6 sprigs fresh parsley Pour cups of water into a medium bowl and sprinkle with the gelatin Set aside until the gelatin is hydrated, about 10 minutes Meanwhile, put the onions, carrots, celery, leek, mushrooms, apples, bay leaves, peppercorns, fennel, coriander, and parsley in a large Dutch oven or stockpot and add cold water to just cover the ingredients Add the hydrated gelatin and water and bring to a simmer over medium heat Adjust the heat to maintain a slow, steady simmer and cook for hour, adding hot water as necessary to keep the ingredients submerged Strain the stock through a fine-mesh strainer lined with cheesecloth into a large bowl and discard the solids Return the stock to the pot, bring to a simmer, and reduce to 2 quarts, about 20 minutes Remove from the heat The stock will keep in an airtight container in the refrigerator for up to days, or it can be frozen for up to months (see here) ... necessary to keep the ingredients submerged Strain the stock through a fine-mesh strainer lined with cheesecloth into a large bowl and discard the solids Return the stock to the pot, bring to a simmer, and reduce... to 2 quarts, about 20 minutes Remove from the heat The stock will keep in an airtight container in the refrigerator for up to days, or it can be frozen for up to months (see here) ... Pour cups of water into a medium bowl and sprinkle with the gelatin Set aside until the gelatin is hydrated, about 10 minutes Meanwhile, put the onions, carrots, celery, leek, mushrooms, apples,