Whisk together all garlic sauce ingredients. Refrigerate until ready to serve.
Place zucchini, sweet potato and onion in a large strainer and toss with 1 tsp salt. Press firmly to drain some water from the vegetables. Let sit.
Meanwhile, line a large bowl with a dish towel. Fold over town and press down to release as much liquid as possible. Repeat for 5-10 minutes until little moisture remains. Let sit for 45 minutes, then press again.
NOTE: You want to remove as much moisture as possible, otherwise the fritters will become soggy when cooked.
Place egg substitute in a large bowl, then whisk in garlic, parsley, mint, remaining 1/2 tsp salt and pepper. Fold in the vegetable mixture, then add cornmeal and cornstarch until combined.
Heat olive oil in skillet over medium-high heat. Once hot, use a Tablespoon to scoop fritters into pan. Flatten with a spatula. Cook until golden brown, about 3 minutes on each side. Transfer to a plate lined with paper towel.