What Mahue said .. and consider adding to the broth as it is simmering .. i use two full marrow bones, cut into segments in a very big pot with: 2-3 hands of garlic cut cross, 2-3 onions cut across, a big handful of fresh rosemary and a big bunch of fresh thyme. I salt the bones after blanching but before roasting

Strain the broth at the end and skim any remaining fat .. there are no rules 🤝