In a large mixing bowl, whisk together the flour, cold water, and beaten egg until smooth. Add salt and black pepper to combine.

Finely chop green onions, grate a carrot, and squeeze excess moisture from zucchini. Fold them into the batter and let it rest for 5-10 minutes.

Heat a non-stick skillet over medium-high heat and add vegetable oil, swirling to coat evenly.

Ladle about ½ cup of batter onto the skillet, spreading it into a thin circle. Cook for 3-4 minutes until golden, then flip and cook another 3-4 minutes.

Remove the pancake from the skillet and let it drain on a paper towel. Repeat the process with remaining batter.

For dipping sauce, combine soy sauce, rice vinegar, and sugar in a bowl. Sprinkle with sesame seeds to finish.