In a medium pot, heat 2 tablespoons of vegetable oil over medium-high heat. Add 2 cups of well-fermented kimchi, 1 finely sliced onion, and 2 minced garlic cloves. Stir-fry for about 5-7 minutes until the onion is translucent and soft.

Pour in 4 cups of water and 1/4 cup of kimchi juice, bringing the mixture to a boil. Then, add 2 teaspoons of gochugaru, 1 teaspoon of gochujang, and 1/2 tablespoon of soy sauce.

Carefully add 12 to 14 ounces of drained, bite-sized firm tofu pieces into the bubbling broth. Allow to cook for about 15 minutes.

After simmering, turn off the heat, and stir in a handful of finely chopped green onions for freshness. Taste and adjust salt if necessary.

Ladle your soup into bowls, serving it hot alongside fluffy steamed rice.