This delicious soup has been on my Must Make list for a while. It's freezing (i.e. Chicago cold) in the Bay State today, so this brothy, beefy, light, deliciousness is hitting the spot. Warning: roasting the beef bones made our house smell horrible, in my opinion. Like Upton Sinclair, Back of the Yards, awful.
Roast 2 pounds beef bones (with marrow) in 450 degree oven for 15 minutes. Then add 1 quartered onion, 5 cloves garlic, 3-inch piece peeled ginger to pan of bones. Drizzle with vegetable oil and toss to coat. Roast another 30 minutes. Stir occasionally.
Fill stock pot with 3 quarts water, add beef bones and onion mixture, 5 star anise, 1 cinnamon stock, 5 black peppercorns, 1 tsp salt, and bunch of cilantro. Bring to boil and simmer for 1-2 hours, until broth is medium brown. Strain liquid through cheesecloth-lined sieve into sauce pan.
Add 1/4 cup fish sauce, 1 tbs rice vinegar, place over low heat and keep at low boil. Meanwhile, soften rice or egg noodles and thinly slice a sirloin steak against the grain. Make an onion relish with thinly sliced yellow onion, thinly sliced radish, 1 tbs rice vinegar, chopped cilantro, and 1 tsp Sriracha sauce. Place the noodles, raw steak slices in the bottom of a bowl, add the simmering broth to cover. Top with onion relish. Enjoy!