Rinse the bone marrow bones under cold water
Soak the bones in salted cold water for 12 to 24 hours, changing the water once or twice
Drain and pat the bones dry
Preheat the oven to 450°F to 475°F
Place the bones upright on a baking tray
Roast for 15 to 25 minutes until the marrow is soft and bubbling
Remove from the oven and let cool slightly
Serve immediately with salt, pepper, and toasted bread if desired