01 - Preheat oven to 430°F. Arrange beef bones and meat on a large roasting pan and roast for 30 minutes until deeply browned.
02 - Transfer roasted bones and meat to a large stockpot. Add carrots, celery, onions, leek, and garlic.
03 - Pour cold water over ingredients until fully submerged. Bring to a gentle boil over medium-high heat, then reduce heat to low.
04 - During the first 30 minutes of simmering, skim off foam and impurities that rise to the surface.
05 - Incorporate bay leaves, peppercorns, parsley, thyme, and salt. Continue simmering uncovered for 3.5 hours at a low, gentle heat.
06 - Regularly skim fat and impurities from the surface throughout cooking to ensure a clear broth.
07 - Remove from heat and strain through a fine mesh sieve or cheesecloth into a clean container, discarding solids.
08 - Allow broth to cool, then refrigerate. Once cold, remove any solidified fat from the surface.
09 - Adjust seasoning if necessary before use. Store appropriately or freeze in portions.