Wash the perilla leaves and Korean mint leaves thoroughly in cold water, then shake off the excess water.

In a large bowl, combine all-purpose flour and water. Add doenjang (Korean soybean paste) and gochujang (Korean hot pepper paste), then whisk until the batter is smooth.

Cut off the tough stems from the perilla leaves. Roll them up, slice them thinly, and then chop them roughly.

Chop the Korean mint leaves, slice the onion and green chili pepper.

Add the chopped perilla leaves, mint, onion, and chili pepper to the batter and mix everything together until well combined.

Heat a large non-stick skillet over medium heat. Add cooking oil and swirl to coat. Pour all the batter into the pan and spread it out evenly.

Cook for about 5 minutes over medium heat until the bottom is golden brown and crispy, then carefully flip the pancake.

Increase the heat to medium-high and cook for another 3 minutes. Flip it one more time and cook for 1 more minute until both sides are well-cooked and crispy.

Transfer the pancake to a cutting board, let it cool for a moment, and then cut it into bite-sized pieces to serve.