Spread zucchini, potato and onion on a clean kitchen towel. Top with another clean kitchen towel and press out as much moisture as possible. Place vegetables in a large bowl with egg, breadcrumbs, flour, garlic powder and baking soda. Season with salt and pepper. Stir until completely combined and ingredients are evenly distributed
Heat 1 tablespoon oil in a large non-stick frying pan over medium heat. Pour 1/4 cup fritter batter into pan and flatten with a spatula until even. Repeat to make 3 more fritters. Cook fritters for 3-4 minutes or until golden underneath. Turn and cook for 2-3 minutes or until other side is golden and fritters are cooked through. Transfer to a plate and keep warm. Repeat with remaining batter, adding more oil if necessary
Scoop flesh from 1 avocado and process in a blender or small food processor until smooth. Transfer to a bowl. Add hollandaise and fold until well combined
Thinly slice remaining avocado. Top fritters with salmon and sliced avocado, then sprinkle with dukkah. Serve with avocado hollandaise to dollop
