Hobak Buchim (Zucchini Pancakes)

Name: Hobak Buchim (Zucchini Pancakes)
Cuisine: Asian, Korean
Ingredients: 1 medium zucchini (about 8 ounces); 1/2 teaspoon salt; 1/4 medium sweet onion (thinly sliced); 2 green hot chili peppers (thinly sliced); 1/2 cup buchim garu (Korean savory pancake mix) (or flour (see note)); 1 large egg (omit for a vegan version and add some water); vegetable or canola oil for frying; 1 tablespoon soy sauce; 1 teaspoon vinegar; 1 tablespoon water; 1/2 teaspoon sugar; pinch of black pepper; pinch gochugaru (Korean red chili pepper flakes)