Wash the sweet potato, peel the skin and cut it into small chunks (not too thick as it will take longer to cook through), Soak them in cold water for 30 minutes to reduce the starch
Drain away the water and thoroughly wipe off the water from the sweet potatoes with kitchen paper.
Pour the deep frying oil into a large pot and heat it up until it reaches 180 C / 356 F
(or boiling). Add the sweet potatoes and cook them until cooked through (about 5 to 8 minutes).
Take out the fried sweet potatoes and place them onto some kitchen paper to soak away the excess oil
Add the cooking oil in a well-heated pan and scatter the sugar around Melt it over medium-high heat until the sugar dissolves then quickly reduce the heat to low Add the sweet potatoes into the pan and mix well with the sauce (for I to 2 minutes).
Move the sweet potatoes onto non-stick baking paper to cool down for 3 to 5 minutes.
Serve, (You can garnish with some crushed nuts or sesame seeds for an extra savory taste. Enjoy!