01 - Preheat oven to 430°F. Arrange beef bones and shank on a roasting pan. Roast for 30 minutes, turning once, until deeply browned.
02 - Transfer roasted bones and meat to a large stockpot. Add carrots, celery, onion, leek, and garlic.
03 - Pour in cold water to cover ingredients by approximately 1 inch.
04 - Bring mixture to a gentle boil over medium-high heat.
05 - Reduce heat to low to maintain a gentle simmer. Skim foam and impurities from the surface during the first 30 minutes.
06 - Incorporate bay leaves, peppercorns, parsley, thyme, and salt into the pot.
07 - Simmer uncovered for 2.5 hours, occasionally skimming fat and impurities. Replenish water as needed to keep ingredients submerged.
08 - Remove pot from heat. Strain broth through a fine-mesh sieve or cheesecloth into a clean container, discarding solids.
09 - Cool broth rapidly then refrigerate or freeze. Remove solidified fat before use if desired.