In a large bowl, mix zucchini, potato and onion. In a separate bowl, whisk eggs and add to the zucchini mixture. Add the flour, breadcrumbs, pepper, garlic powder and salt and mix gently but until thoroughly combined.

In a large nonstick frying pan heat oil over medium heat. When oil is hot, place about 3 tablespoons of batter into oil and fry until crisp, turning to fry on the other side. Add small amounts of oil as needed when frying. Turn out on towel paper to drain. Serve quickly, best while hot.