Soy Dipping Sauce
3 tablespoons unseasoned rice vinegar
1 tablespoon reduced-sodium soy sauce
1 ½ teaspoons sugar
Crushed red pepper flakes
1 ½ pounds zucchini (about 3 medium), grated
½ teaspoon kosher salt plus more for seasoning
1 large egg
¼ cup all-purpose flour
3 tablespoons finely chopped fresh chives
1 tablespoon cornstarch
Freshly ground black pepper
⅓ cup vegetable oil
Cook's Note: You can make these 30 minutes ahead and keep them warm in an over heated to 200F.
Mix vinegar, soy sauce, sugar, and a pinch of red pepper flakes in a small bowl until sugar is dissolved. Set aside.
Place zucchini in a colander set in the sink and toss with ½ teaspoons salt. Let stand 10 minutes, then wring zucchini dry in a clean kitchen towel. Squeeze out as much liquid as possible before proceeding.
Place zucchini in a large bowl and gently mix in egg, flour, chives, and cornstarch; season with salt and pepper.
Heat oil in a large skillet over medium heat. Working in 2 batches, drop a ¼ zucchini mixture into skillet, flattening slightly; cook until golden and crisp, about 3 minutes per side. Transfer fritters to a paper towel–lined plate; season with salt. Serve with soy dipping sauce.