Grate the potatoes and onion, then squeeze out as much moisture as possible using a clean kitchen towel.
In a large bowl, combine the grated potatoes, onion, eggs, flour, cornstarch, garlic powder, salt, pepper, and parsley. Mix until well combined.
Heat about ¼ inch of oil in a large skillet over medium heat.
Scoop about ¼ cup of the potato mixture into the skillet and flatten gently with a spatula. Cook for 3–4 minutes per side, or until golden brown and crispy.
Transfer to a paper towel-lined plate to drain excess oil. Repeat with the remaining mixture.
Serve hot with sour cream, chopped chives, or applesauce.
