In Japan, these cabbage and mushroom pancakes, known as okonomiyaki, are most commonly filled with pork and shrimp before they're cooked, but they can also be stuffed with beef or chicken and other kinds of seafood.Plus: More Pork Recipes and Tips
In a large bowl, whisk the flour into the eggs until a smooth batter forms. Add the shredded cabbage, sliced shiitake, 3/4 teaspoon of salt and 1 tablespoon each of the pickled ginger and bonito flakes. Mix until thoroughly combined. In a small bowl, combine the pork and shrimp and season lightly with salt and pepper.
In a small saucepan, whisk together the mirin, soy sauce, Worcestershire sauce and ketchup. Bring the sauce just to a boil, then simmer over moderately low heat until thickened slightly, about 5 minutes. Remove the saucepan from the heat.
In a 12-inch nonstick skillet, heat the vegetable oil. Stir the pancake mixture. Spoon four 1-cup portions of the pancake mixture into the skillet and flatten each into a 5-inch pancake about 1/2 inch thick. Cook the pancakes over moderate heat until they are golden brown on the bottom, 5 to 7 minutes. If the pancakes brown too quickly, lower the heat slightly.
Make a slight indentation in the top of each pancake and top each of them with one-fourth of the pork and shrimp, pressing down slightly. Carefully turn the pancakes over; if necessary, use two spatulas to hold the pancakes together. Cook the pancakes until they are golden brown on the second side and the pork and shrimp are cooked through, about 6 minutes.
Transfer the pancakes to a platter, pork and shrimp side up. Brush the pancakes with some of the sauce and top each of them with a little pickled ginger and some bonito and nori flakes. Serve the pancakes hot, with the remaining sauce and mayonnaise on the side.
Plain stir-fried noodles or Stir-Fried Noodles and Pork.