Julienne the zucchini, yellow potatoes, carrot, and red onion. Place them in a large bowl with two of the pressed garlic cloves and sliced chili pepper, if using. Toss to combine.
Whisk the flour and cornstarch together in a medium bowl. Add the ice-cold water and whisk until a thick, smooth batter forms.
Pour the batter over the vegetables and stir until all of the vegetables are evenly coated.
Heat enough oil to coat the bottom of a cast iron skillet over medium heat.
Spoon portions of the vegetable mixture into the hot skillet and gently flatten each into an even layer.
Cook until the bottom is golden brown and crisp. Flip and cook the second side until golden brown and the vegetables are tender. Repeat with the remaining batter, adding more oil as needed.
Whisk together the liquid aminos, sesame oil, honey, rice vinegar, sesame seeds, and the remaining garlic clove in a small bowl until well combined.
Cut the pancakes into quarters, garnish with sliced scallions, and serve immediately with the dipping sauce.
Notes
Use ice-cold water when preparing the batter for the lightest, crispiest texture.
Julienne the vegetables into thin, evenly sized pieces so they cook at the same rate.
If the vegetables release excess moisture after slicing, pat them dry before adding the batter.
Add oil between batches as needed to keep the bottom of the skillet lightly coated.
Store leftover pancakes in an airtight container in the refrigerator for up to 3 days.
Reheat in a lightly oiled skillet over medium heat to restore their crispy exterior.