Over medium-high heat, add all the ingredients for the stock in a deep saucepan. Bring to a boil and then reduce the heat to medium-low. Simmer for 20 minutes. While it is simmering, make sure the water level stays the same. Strain the broth to remove all the pieces. Set the broth aside.
Combine the kimchi juice, soy sauce, gochujang, garlic paste, ginger paste, sugar, and sesame oil in a small boil.
Saute the onions, shiitake mushrooms, and king oyster mushrooms over medium-high heat in a pot. Saute until everything has softened and slightly browned, about 10 minutes.
Add the bowl of mixed sauces and kimchi to the pot and stir in well. Allow to cook for about 2 minutes. Carefully add the stock and mix together really well.
Bring to a boil. Reduce the heat to medium and bring the mixture to a light simmer. Add the tofu and cook uncovered for 8 minutes. After 8 minutes, flip the tofu and cook for another 5 minutes.
Add the enoki mushrooms and cook for 3 more minutes. Serve over a bowl of rice and top with sesame seeds and green onions.