Vietnamese Pho with Beef Marrow Bones (Crowd Cow)

Ingredients

• 4 lbs marrow bones
• 1 large yellow onion, cut in half
• 5 2-inch slices of ginger
• 2 pieces star anise
• 1 cinnamon stick
• 2 tbsp fish sauce
• 1 lb flank, sirloin or coulotte steak, cut into very thin slices
• ½ lb dry rice noodles