Step 1
Use either leftover rib bones from a roast, or purchase a bag of beef bones from your butcher. Turn the bones into a large roasting pan, add a handful of vegetables such as carrot chunks and tops, celery chunks, onion pieces with skin on, and season with salt and pepper.Roast for 30 minutes 

Step 2
Add the roasted bones and vegetables to a large deep pot with some fresh sprigs of thyme, rosemary, or another woody herb of your choice, then pour in enough cold water to cover completely. 

Step 3
Bring to a boil, then reduce to a gentle simmer. Cook with the lid half on for about 1 hour, skimming off any fat that comes to the top of the pan, if necessary.

Step 4
Remove the bones and discard, then pour the liquid through a sieve into a large storage container.