Zucchini Fritters

INGREDIENTS

• 3 unseasoned rice vinegar
• 1 reduced-sodium soy sauce
• 1 1/2 sugar
• Crushed red pepper flakes
• 1 1/2 zucchini (about 3 medium), grated
• 1/2 kosher salt plus more for seasoning
• 1 large egg
• 1/4 all-purpose flour
• 3 finely chopped fresh chives
• 1 cornstarch
• Freshly ground black pepper
• 1/3 vegetable oil