1. Peel the lotus root skin, slice them 4 to 5 mm in width and soak in water for about 10 mins.
2. Meanwhile, in a medium bowl, put together well drained canned tuna and onion. Pour into mayonnaise, tsuyu or soy sauce and sugar. Mix well with wood spoon or hands until the mixture gets sticky and set aside.
3. Combine 2 eggs with milk. For the lotus root, gently pat them dry with a paper towel, salt and pepper both sides. On a slice of lotus root, place about 2 tbsp filling and spread. Cover another slice of lotus root on top and press down to make a sandwich!
4. Coat with flour thinly. then dip into egg (mixed with milk), and finally coat thoroughly with Panko (bread crumbs).
5. Put a tiny amount of panko to check the oil is ready. If it sizzles, it's ready! (or stick a chopstick in the oil and see if bubbles start to appear around the chopstick.) Removing excess panko, press them gently. Fry them both sides until browned.