Cut the pork, onion, tofu, and green onion into bite-sized pieces.
Place the pork in a pot and stir-fry over medium heat without oil.
Add the kimchi and stir-fry together.
Add red pepper powder and stir-fry for another 1-2 minutes.
Pour in water or broth and bring to a boil.
When it starts boiling, add the tofu and onion.
Season with soy sauce and salt to taste.
Add green onion and simmer once more before serving.