For the broth:

1. Season the short ribs with kosher salt and pepper. Heat your largest, heavy-bottomed pot on medium high. When pot is hot add olive oil and heat until shimmering. Sear each short rib on all four sides to obtain a nice crust. Do not over crowd the short ribs or they will steam instead of sear. You will likely need to work in batches even if you have a very large pot. Remove the ribs as they sear and set aside on a platter. Pour out all but a couple tablespoons of the leftover fat in the pot.
2. Trim your green onions to separate the white and green parts. Put the green parts in the fridge to use as garnish when you are ready to serve. Heat the residual fat over medium heat and add white parts of green onions, garlic and ginger. Cook until they begin to color, stirring frequently for about 4 minutes. Add the remaining spices: star anise, cinnamon, cloves, peppercorns and coriander seeds and cook a minute or two. 
3. Deglaze with the wine, stirring and scraping the bottom of the pan with a wooden spoon. Reduce until liquid is mostly evaporated. Add the seared ribs back to the pot along with the chicken broth, beef broth and soy sauce. Bring to a boil, reduce heat to a simmer and partially cover the pot with a lid. Cook for 90 minutes until the beef is tender and begins to fall off the bone. 
4. Remove the short ribs including bones and meat from the pot and set aside to cool. Discard the bones and shred the meat into bite sized pieces. The meat will be fatty and grisly in places. That is OK. Discard the very fattiest and grisly pieces, but retain a little of the fat for flavor. 
5. Strain the broth through a strainer and then return the broth to the pot. As an optional step, particularly if you are taking two days to make the soup, I like to refrigerate the broth at this point so the remaining fat coagulates on the surface, making it easy to remove. I don’t remove 100% of the fat, because I think it enhances the flavor. Once the broth is strained and the excess fat removed you can add the shredded meat back to the broth.

For the onions:

1. Heat your pan over medium flame and add the olive oil or a mixture of olive oil and butter or ghee. Add your onions and a healthy pinch of kosher salt. The salt helps to pull the water out of the onions, which is the first step in caramelization.
2. Lower the heat to somewhere between medium low and low, low enough so your onions cook slowly and don’t burn. Stir frequently in the beginning, scraping up any of the bits that start to color on the bottom of the pan. When the pan gets dry and the onions start to stick, add a splash of broth or wine to deglaze the pan. The pan will immediately begin to steam and release the onions.  Give the pan a good scrape with a wooden spoon to remove all the bits from the bottom of the pan. Feel free to deglaze as needed. 
3. Continue cooking and stirring until the onions are golden brown, about 40 minutes total. 

Putting it all together:

1. Combine the finished broth, shredded meat and onions in a large soup pot. Bring the pot to a boil and reduce heat to low for about 30 minutes. 
2. Add rice vinegar to taste.

Cook the noodles:

1. Cook your noodles to the package directions. They typically only take a couple minutes. Strain out the cooking water and place noodles in the bottom of oversized soup bowls. Add broth to each bowl.

Garnish:

1. Garnish with sliced green onions, egg halves, radish slices, bok choy or spinach. Finish with a squeeze of lime and sriracha to taste.