01 - Preheat oven to 430°F. Arrange beef bones and stew meat on a roasting pan. Roast for 40 minutes, turning halfway, until deeply browned.
02 - Add onions, carrots, celery, leek, and garlic to the pan. Roast for an additional 15 minutes to caramelize.
03 - Transfer browned bones, meat, and vegetables to a large stockpot. Remove excess fat from the roasting pan.
04 - Place roasting pan over medium heat, add tomato paste and stir 2 minutes. Pour in 1 cup cold water, scraping browned bits, then transfer mixture to stockpot.
05 - Pour remaining cold water into stockpot, ensuring ingredients are fully submerged. Add bay leaves, thyme, parsley, peppercorns, and cloves.
06 - Bring to a gentle simmer without boiling. Skim foam and impurities from surface regularly.
07 - Maintain uncovered simmer for 3 to 4 hours, occasionally skimming and topping with water to keep solids covered.
08 - Pour stock through a fine-mesh sieve into a clean pot or bowl, discarding solids.
09 - If desired, cool stock to solidify surface fat and remove it for clarity. Season with salt just before use or storage.