Step 1

Gather all the ingredients.

Step 2

Carefully wash the sweet potatoes (Don’t peel the skin). Cut the sweet potatoes diagonally while rotating the sweet potato a quarter between cuts. This Japanese cutting technique is called “Rangiri”.

Step 3

Put the sweet potatoes in 8 cups water and add 2 tsp salt. Soak for 15 minutes to remove starch.

Step 4

Add the oil in the medium pot (I use a 2.75-QT Staub) and bring it to 320 ºF (160 ºC) (Use a cooking thermometer helps!). Meanwhile, dry the sweet potatoes with the kitchen towel (or paper towel).

Step 5

When the oil has reached 320 ºF (160 ºC), add the sweet potatoes (half of them) into the oil and deep fry. Do not crowd the pot and fry in batches (I do twice).

Step 6

Deep fry until golden brown, about 10 minutes.

Step 7

When it's golden brown, insert a wooden skewer to make sure it goes through. Transfer to a wire rack or a paper towel to drain the oil.

Step 8

To make candy (syrup), combine 5 Tbsp sugar, 1 ½ Tbsp water, and 1 Tbsp Mirin in a large frying pan off the heat. Put on the stove and bring it to boil on medium heat.

Step 9

Once the mixture is bubbling, add 1 tsp vinegar and 1 tsp soy sauce.

Step 10

Reduce the mixture, stirring constantly, until the right consistency. When you can draw a line on the pan, add the sweet potatoes.

Step 11

Turn off the heat and coat the sweet potatoes with syrup. Sprinkle black sesame seeds (once the candy is hardened, sesame seeds won't stick to the surface, so do it while candy is soft).

Step 12

Serve on a plate or bowl. Enjoy!

Step 13

Gather all the ingredients.

Step 14

Carefully wash the sweet potatoes (Don’t peel the skin).

Step 15

Cut the sweet potatoes diagonally while rotating the sweet potato a quarter between cuts. This Japanese cutting technique is called “Rangiri”.

Step 16

Soak sweet potatoes in water for 15 minutes to remove starch.

Step 17

Do not heat the frying pan yet. Add sugar, oil, soy sauce and rice vinegar in the pan and combine all together.

Step 18

Dry the sweet potatoes completely with paper towel and place in the pan.

Step 19

Wrap the frying pan’s lid with kitchen cloth. This is to prevent condensation on the lid dripping into sweet potatoes while cooking.

Step 20

Cover with the lid and turn on the heat to medium.

Step 21

When you hear bubbling sound from the pan, turn the heat to low to medium-low, and set timer for 2 minutes. Open the lid and flip the sweet potatoes every 2-3 minute so that all sides will have nice golden brown color and get flavored.

Step 22

Depends on the size of sweet potatoes, the cooking time varies, cook for 8-10 minutes or until an inserted skewer goes through smoothly (I personally prefer it a bit tougher than completely soft texture). Transfer to the serving plate/bowl and sprinkle black sesame seeds.