Add the potatoes to cold, salted (2 tsp salt) water and then bring to a boil until cooked.(or heat in a microwave oven until tendered) Drain and sprinkle them with salt and pepper and mash.
Heat the 1 tbsp oil in a pan, put chopped onion and ground pork and stir fry well until they change color. Add sugar and soy sauce, keep stirring well over medium heat until the liquid is almost gone.
Combine mashed potatoes and ②'s step mixture, and milk(or cream) well. Season with salt and pepper to your taste. Let them cool.
Make easy-to-eat size shape.
Place flour, beaten egg, and panko bread crumbs in separate bowls. Dust the croquettes with flour and shake off any excess, then dip in the beaten egg and coat evenly. Roll them in bread crumbs and coat throughly, pressing the bread crumbs in by hand.
Heat the vegetable oil for deep frying to 180℃ (355℉) in a pot. Deep-fry the potatoes on both side until the bread crumbs are golden brown.