Heat vegetable oil in a medium pot over medium heat.
Add chopped kimchi to the pot and sauté for 3 to 4 minutes until slightly softened and fragrant.
Add rinsed rice to the pot and stir well to combine with the kimchi.
Pour in water and kimchi juice, then add gochujang, soy sauce, and salt. Stir to evenly distribute the ingredients.
Bring the mixture to a boil, then reduce heat to low and cover the pot with a tight-fitting lid.
Simmer for 15 minutes without lifting the lid, until the rice is cooked and liquid is absorbed.
Remove the pot from heat and let it sit covered for 5 minutes to steam.
Drizzle sesame oil over the rice and gently fluff with a fork.
Garnish with sliced green onions and toasted sesame seeds before serving.