Roast beef bones at 425°F for 30 minutes.

In a large pot, combine roasted bones, onion, ginger, star anise, cloves, cinnamon stick, and coriander seeds. Cover with 12 cups of water and bring to a boil.

Reduce heat and simmer for 3-4 hours, skimming any foam that rises to the top.

Strain the broth, discarding solids. Return the broth to the pot and add fish sauce and sugar. Simmer for another 30 minutes.

Cook rice noodles according to package instructions. Drain and divide noodles into bowls.

Top each bowl with thinly sliced beef. Pour hot broth over the beef and noodles.

Serve immediately with bean sprouts, basil leaves, lime wedges, and jalapenos.