Place the pork trotters, chicken feet, and chicken wings in a stock pot and cover with cold water. Bring to a rapid boil. There will be a decent amount of scum.
Remove from the heat and pour into a strainer. Carefully wash all the pieces under cold water and remove any coagulated blood. Set aside for now.
Fill a large pot with kombu, dried anchovies, and 6 quarts of water. Bring to a low simmer and turn off the heat. Let this sit for 10 minutes.
Remove the kombu and dried anchovies. Turn the heat on and add the dried shiitake mushrooms and bacon to the pot. Make sure to keep an eye on the water level. You want to end up with 6 quarts of broth.
Bring to a boil and simmer for 1 hour. Make sure to keep an eye on the water level and to remove any foam that forms.
After it has simmered, remove the mushrooms and bacon pieces. Add the pork and chicken pieces to the pot.
Add the scallions, onion, leek, carrots, ginger, and garlic to the pot. Allow this to simmer for 6-8 hours. While it is simmering again, make sure to keep the water level the same and to remove any foam that appears at the top.
Once the broth is ready, strain all the pieces out and you have your broth. Make sure it is warm when you are ready to serve it.