Trim the ends of your zucchini and shred it using the large holes of a grater. You can also use the shredding attachment on a food processor if you have one.
Place the shredded zucchini in a strainer over a bowl or in the sink. Toss with the salt and let sit for 10 minutes.
While the zucchini sits, get out a large mixing bowl. Add the ground flaxseeds and water to it, stir a little and set aside to thicken for a few minutes.
Once the zucchini has rested for 10 minutes, use your hands to squeeze out all of the excess liquid you can, and place the squeezed zucchini in the bowl with the flaxseed mixture. Don't skip this part or the fritters will turn out soggy.
To the same bowl, add the flour, cornstarch, baking powder, green onions and optional fresh dill or parsley. Stir with the zucchini until well incorporated.
In a large pan (non-stick or cast iron preferred), heat 3-4 tablespoons of oil over medium heat. When the oil is hot, add about 2 tablespoons of the zucchini mixture to the pan, and flatten the tops with the back of a spoon. Fry for 2-3 minutes, then flip and cook for another 2-3 minutes until golden brown.
Repeat with all of the fritter mixture, adding more oil as needed. If you have a really good non-stick pan you may not need much oil at all. Place the cooked fritters on a paper towel lined plate.
Serve immediately with vegan sour cream and enjoy!