Place the beef shank bones in the slow cooker. If one side is closed and the other side open with the marrow exposed, place the bones closed side down to prevent the marrow from falling out.
Add the garlic cloves, onion halves, rosemary, salt and pepper to the bones.
Pour in one and a half to two liters of water (depending on the size of your slow cooker).
Set the slow cooker on LOW and leave for twelve hours.
Place the beef shank bones in soup bowls.
Taste the broth; add more salt and pepper, if needed. Strain.
Pour strained broth over the beef shank bones.
Sprinkle in finely sliced scallions before serving your no-frills slow cooker beef bone marrow soup. Remember to supple a teaspoon with a long handle, a wooden spatula or a popsicle stick for scooping out the bone marrow, or a large straw for sipping it instead.
No-frills Slow Cooker Beef Bone Marrow Soup printed from https://casaveneracion.com/no-frills-slow-cooker-beef-bone-marrow-soup/ for personal use only. Not for republication nor distribution.