The large amount of garlic is essential to the broth. It should be firm, unblemished, and without any green sprouts. New California early white garlic can often be found in March, so look for it. New dried garlic can also be used; it is hard to the touch, and the outer skin looks papery and new. Instead of peeling, just smash with a knife to loosen the papers and expose the cloves.
Combine all ingredients in a Dutch oven over medium-high heat; bring to a boil. Reduce heat to medium, and cook for 30 minutes. Strain mixture through a cheesecloth-lined sieve, reserving broth. Discard solids.
Note: Broth may be stored in the refrigerator for up to 2 days or in the freezer for 6 months. Freeze in ice cube trays or 1-cup freezer containers for easy measuring.