In a small bowl, combine chili oil, light soy sauce, sesame oil, rice vinegar, and sugar. Whisk until smooth and set aside.

Finely mince kimchi, and slice onion and green onions. Whisk together flour, cornstarch, and salt. Gradually add seltzer water and kimchi brine, stirring until smooth. Fold in kimchi and onions.

Heat oil in a non-stick frying pan over medium heat for about 2 minutes.

Pour half of the batter into the pan and spread into a thin layer. Cook for 5-6 minutes until edges are crispy.

Carefully flip the pancake and cook for another 4-5 minutes until golden brown.

Slice into wedges and serve hot with dipping sauce. Garnish with extra green onions and sesame seeds if desired.