Mix the sauce ingredients (water, soy sauce, minced garlic, corn syrup, black pepper) in a bowl and set aside.

Blanch the smoked duck briefly in boiling water to remove excess grease, then drain and pat dry.

Cut the vegetables (potato, onion, bell pepper, green chilies) into bite-sized pieces.

Heat a small amount of cooking oil in a frying pan and sauté the potato slices until golden brown on both sides.

Add the prepared sauce to the pan with the potatoes and bring it to a boil.

Add the remaining vegetables (onion, bell pepper, green chilies) to the pan and stir-fry until the sauce thickens and coats everything.