Ramen Tonkotsu Ramen - Japanese Noodle Soup

Broth:

Soak pork bones in cold water for 1 hour.
Drain the water after an hour, rinse the bones.
Transfer to a saucepan and pour water so that the water is 3-5 cm above the bones.
Put the pan on high heat. After the water boils, cook for 10 minutes, removing the foam.
After 10 minutes, drain the water, rinse the bones in cold water and wash the pan.
Then put the bones in a clean saucepan, pour cold water 3-5 cm above the bones, add onion,
green onion, ginger and garlic.
Bring to a boil, reduce the heat to medium-low, cover with a lid.
Cook for 6-12 hours, stir occasionally. (I cooked for 6 hours in a saucepan, then moved everything to a slow cooker and left it in preheating mode overnight)
Strain the finished broth.

Pork Bowl:

Twist pork into a roll and tighten with a thread.
Fry in a very heated frying pan with 1 tbsp oil on all sides.
Add water, sake, mirin, soy sauce, sugar, ginger and leek to the pan.
Put the pan on the fire, bring to a boil.
Put the pork in the sauce, cover with foil, cook for 10 minutes.
After 10 minutes, turn the meat over, reduce the heat to a minimum, cover with foil and lid.
Cook for 2 hours, turning the pork every 15-20 minutes.
Remove the pan from the heat and allow to cool, then put it in the refrigerator for at least 6 hours (it is best to leave overnight).
Before serving, remove all the threads, cut the pork into circles and, if desired, fry for 30 seconds on high heat.
Strain the pork sauce, we will need it for broth.

Ramen:
Broth:
Add fish sauce and half of the sauce from the pork bowl to the bone broth, mix.

For ramen:
Boil soy sprouts in boiling water for 1 min, then rinse in cold water.
Boil the noodles and rinse them under cold water.
Finely chop the green onion, cut the egg in half.

Assembly:
Put noodles in a large bowl, put pork bowl, soy sprouts, egg on top.
Pour broth on top, sprinkle with green onions, add soy sauce to taste.