Gather beef bones, beef scraps, onion, carrot, celery, garlic, bay leaves, peppercorns, and water
Roast the beef bones and scraps in a hot oven until browned
Place the roasted bones and scraps in a large stockpot
Add chopped onion, carrot, celery, garlic, bay leaves, and peppercorns
Cover with cold water
Bring to a gentle simmer
Skim off any foam or impurities from the surface
Keep the stock at a low simmer for several hours
Add water as needed to keep the ingredients covered
Strain the stock through a fine sieve or cheesecloth
Discard the solids
Cool the stock quickly
Refrigerate and remove any fat from the surface
Store in the refrigerator or freeze for later use