In a large bowl, whisk together the flour, eggs, cabbage, scallions, mushrooms, shrimp, salt, pepper, ginger, and garlic powder until combined.
Heat a large non-stick skillet over medium-high heat. Add the vegetable oil and swirl it around the pan.
Pour a quarter cup of the batter into the skillet and spread it out into a thin round shape. Cook for about 2 minutes until the edges are lightly browned.
Flip the pancake and cook for an additional 2 minutes until the other side is lightly browned.
Remove the pancake from the skillet and repeat with the remaining batter.
Serve the pancakes with your favorite sauce and bonito flakes, if desired.