Beef Bone Broth

Arrange racks in upper and lower thirds of oven; preheat to 400 degrees F.

Place soup bones on a rimmed baking sheet and drizzle with oil. Roast on the bottom rack for 30 minutes.

Combine carrots, celery, onions, tomatoes and garlic on a second rimmed baking sheet. Move the bones to the upper rack and place the vegetables on the lower rack. Roast until the bones are deep brown and the vegetables are starting to brown in spots, 30 to 45 minutes more.

Transfer the bones and vegetables to a 10- to 12-quart stockpot. Add 1 cup water to the bone pan and scrape up any browned bits with a wooden spoon; add to the pot. Add the remaining 15 cups water, vinegar, thyme, bay leaves, peppercorns and salt. Cover and bring to a boil over high heat. Reduce heat to maintain a low simmer and cook, covered, for 8 hours.

Remove the bones (if desired, remove any meat from the bones and save for another use). Strain the broth through a large sieve into a large bowl; discard the solids. Skim fat from the surface, if desired.