Whisk together the flours and salt in a medium bowl. Whisk in 2 1/4 cups cold water. Fold in the oysters, shrimp, and scallions. Heat 2 tablespoons of vegetable oil in a large nonstick skillet over medium-high heat. Ladle in a generous cup of the batter (try to get an equal amount of seafood in each pancake) and cook until browned and crisp on the first side, 2 to 4 minutes. Carefully flip the pancake and cook on the second side until browned and crispy, another 2 to 3 minutes. Continue with the remaining batter and more oil as necessary. Serve hot with the Scallion Dipping Sauce.
Combine everything in a small bowl and whisk until combined.
Scallion Dipping Sauce: I serve this with all sorts of savory pancakes and dumplings. It's even great for simple roast chicken.
Reprinted from: The Kimchi Chronicles (c) 2011 by Marja Vongerichten. Permission granted by Rodale, Inc. Available wherever books are sold.