01 - Place beef bones and optional lean beef in a large pot. Cover with cold water and bring to a boil over medium-high heat.
02 - As the liquid begins to boil, skim off any foam or impurities that rise to the surface.
03 - Add carrot, onion, celery, garlic, bay leaf, peppercorns, parsley, thyme (if using), and salt to the pot.
04 - Reduce heat to low and simmer gently, uncovered, for 40 to 45 minutes, skimming occasionally to maintain clarity.
05 - Strain the broth through a fine-mesh sieve or cheesecloth into a clean container. Discard solids.
06 - Taste and adjust salt as needed. Serve hot in cups as a savory beverage or starter.