Place the kimchi in a bowl and slice it into bite-sized pieces if it’s not already cut.
Thinly slice the onion and finely chop the green onion.
In the bowl with the kimchi, add sugar, gochugaru, minced garlic, sesame oil. Mix everything thoroughly, coating the kimchi evenly with the seasoning.
Heat a pot or pan over medium heat. Grease it with 1 tbsp vegetable oil. Add the seasoned kimchi and sliced onion to the pot.
Stir-fry for 5 minutes, stirring occasionally until the onions soften and the kimchi becomes fragrant.
Once the kimchi is nicely caramelized, add the chopped green onion and stir-fry for 1 more minute to enhance the aroma.