Boil potatoes with enough salt until fork tender. Let them cool, peel the skin, prick all over with a fork, and shallow/deep fry/bake them until golden brown.
Heat oil in a wok, add finely minced ginger, garlic, and fresh red chillies. Saute until ginger garlic are aromatic.
Next, add in chopped onions, saute until translucent.
Add schezwan sauce and sugar.
Mix well, saute for a minute.
Add the cornflour slurry.
Mix well until the mixture has thickened and glossy.
Finally, add the potatoes, toss them in the sauce so they are well coated. Sprinkle with scallion/spring onion greens. Serve hot with fried rice/hakka noodles.