For pa jeon:
1 cup all purpose flour
1 cup rice flour
2 eggs, lightly beaten
1 1/2 cups cold unflavored seltzer water
1 tablespoon canola oil, plus extra for the pan
1 cup garlic chives (scallions are ok), sliced in 2-inch lengths
1/2 cup carrots, peeled cut into thin matchsticks (if you grate them, they disappear into the batter)
1/2 cup shitake mushrooms, sliced
1 tablespoon prepared kimchi, chopped, plus additional for serving

For vinegar dipping sauce:
1/4 cup soy sauce
3 tablespoons rice vinegar (unseasoned)
1/4 teaspoon sesame oil
1 teaspoon sugar
2 teaspoons minced or grated fresh ginger
1 teaspoon toasted sesame seeds