Drain the shredded potatoes, pressing them down in a colander to get their moisture out. Place the potatoes in a bowl; using a box grater, grate the onion directly into the potatoes so that the onion juices fall into bowl as well. Add the egg and plain flour or meal to the bowl then season with spices and salt. Combine and drop enough batter into hot oil to make 2 1/2-inch pancakes. Add more oil, as needed, and fry cakes in batches until deeply golden on each side.
You will get about 16 pancakes. Drain cooked cakes on paper towels.
Cut the avocados in half, all the way around the pit. Remove the pit with a spoon, then scoop the flesh into a bowl and add the lemon juice, onion, garlic, jalapenos and a generous amount of salt. Mash the guacamole to a smooth consistency.
Reduce the pomegranate juice to a syrup.
Arrange the potato pancakes on a platter and top with heaping spoonfuls of guacamole.
Drizzle pomegranate syrup over the guacamole and serve.