Toast beef bones, onion, and ginger until lightly charred
Simmer bones with water for several hours
Skim impurities from the broth
Add star anise, cinnamon, cloves, coriander seeds, and fennel seeds
Add fish sauce, salt, and a little sugar
Strain the broth
Soak rice noodles in warm water until softened
Cook the noodles briefly in boiling water
Slice beef thinly or prepare chicken, tofu, or meatballs
Place noodles in bowls
Add raw beef or cooked protein on top
Ladle hot broth over the noodles
Top with scallions, cilantro, Thai basil, bean sprouts, lime, jalapeños, and hoisin or sriracha if desired