Prepare the vegetables for the sauce. Dice cucumber, carrot, bell pepper, and onion. Ensure to include onion for flavor.

Heat a small amount of oil in a pot and sauté the vegetables until the onion becomes translucent.

Add 2 cups of water and the sauce ingredients (oyster sauce, ketchup, vinegar, sugar) to the pot. Adjust the sweetness and tanginess to your preference.

Thicken the sauce by adding cornstarch mixed with water. Stir until the sauce reaches your desired consistency.

Peel the lotus roots using a peeler and grate them finely.

Mix the grated lotus root with cornstarch, adding one tablespoon at a time until the mixture holds together when scooped.

Scoop the mixture with a spoon and deep-fry in hot oil. Fry once, let it rest, and fry again for extra crispiness.