This makes a much more flavorful vegetable broth that is deeper in flavor and darker in color than most vegetable broths. Feel free to switch the herbs to match any dish you are preparing the stock for. Add salt if you want.
Cut off the pointed end of the garlic just to expose the cloves. Place the garlic and the next 5 ingredients (through turnips) on a large jelly roll pan. Drizzle with oil; toss well. Bake at 450 degrees for 10 minutes.
Add the leeks and mushrooms. Bake an additional 35 minutes or until browned and tender, stirring occasionally.
Spoon the vegetables into a Dutch oven. Pour the wine into the jelly roll pan, scraping to loosen up the browned bits.
Add the wine mixture, 10 cups water, and remaining ingredients to the vegetable mixture.; bring to a boil. Reduce heat, and simmer 1 hour, stirring occasionally.
Strain through a fine sieve over a bowl; discard the solids. Store in an airtight container in the refrigerator for up to 1 week or freeze.