Peel potatoes and onions; cut into pieces for the food processor or grate by hand using mandolin grater
Shred onions and squeeze out all excess liquid; transfer to a large bowl
Add grated potatoes and zucchini directly to the onions without straining
Add eggs, flour or substitute, salt, and pepper; stir until well combined
Warm neutral oil in a large pan over medium-high heat until shimmering, keeping at consistent medium heat
Spoon batter into the pan, flatten gently, and fry until golden, about 4-5 minutes per side
Transfer to a wire rack to keep crispy
Serve hot with sour cream, applesauce, or favorite dipping sauce
For homemade applesauce: grate 2 honey crisp apples, add 1 tbsp sugar and 1 tbsp lemon juice
