Prepare the meat by cutting into small pieces - same for the pork skin (blanch it first). In a medium size pot on medium high heat, sauteed the pork for 5-10 minutes till the fats have been rendered.
Next add in five spice powder, hao chi & white pepper. Followed by rock sugar & saute for a minute or two. Then add in sake, mirin, soy sauce, & dark soy.
Continue braising on medium high heat for 5 to 10 minutes. Add in crispy shallots, water & stock cube. Half covered with lid, and braise on medium low heat for at least 1 hour. Stirring every now and then to make sure the bottom doesn't burn.
While braising prepare a pot of boiling water on medium heat. Add the dry kombu in and leave to a gentle boil for at least 15 mins, then add in bonito flakes - a quick blanch for the flavor, sieve the dashi & add in the knorr beef cube & continue to cook till stock cube no longer visible. Leave to chill and put into fridge/freezer.
Prepare the other ingredients for assembling. Grate the mountain yam into a bowl & set aside to chill. Chop scallions for garnishing. Cook the somen based on package instruction, after cooking, soak in ice water for a minute or two. Remove from ice water, and use a siever to remove as much moisture on the noodles as possible. Add in 1 tbs of oil from the (surface of the braised meato the somen to prevent it from sticking.
To assemble, lay a handful of somen right at the center of the bowl. ladle 1.5 tbs of grated mountain yam on the noodles, followed by 3 tbs of braised meat on the noodles. Add a raw egg yolk right in the center and garnish with scallions & sesame seeds.
To serve, bowl of noodles with chilled beef broth & pickled ginger on the side. There are 2 ways to eat this. Mix the noodles evenly and enjoy the taste of the noodles with mountain yam and the pork. Leave about half a portion left and add in chilled broth to finish up with the noodles.