To Make Version 1: Deep-Fry

Cup of Yum
1. Gather all the ingredients.
2. Carefully wash 1.2 lbs Japanese sweet potatoes (Satsumaimo) (don’t peel the skin). Cut the sweet potatoes diagonally while rotating the sweet potato a quarter turn between cuts. This Japanese cutting technique is called rangiri.
3. Put the sweet potatoes in 8 cups water and add 2 tsp Diamond Crystal kosher salt. Soak for 15 minutes to remove the starch.
4. Add 2 cups neutral oil to a medium pot (I use a 2.75-QT Staub) and bring it to 320ºF (160ºC). Using a cooking thermometer helps determine the temperature. Meanwhile, dry the sweet potatoes with a kitchen towel (or paper towel).
5. When the oil has reached 320ºF (160ºC), add some of sweet potatoes into the oil and deep-fry. Fry in batches (I do 2 batches) and do not crowd the pot.
6. Deep-fry until golden brown, about 10 minutes.
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.
8. To make the syrup, combine 5 Tbsp sugar, 1½ 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.
9. Once the mixture is bubbling, add 1 tsp rice vinegar (unseasoned) and 1 tsp soy sauce.
10. Reduce the mixture, stirring constantly, until the right consistency. When you can draw a line on the pan, add the sweet potatoes.
11. Turn off the heat and coat the sweet potatoes with the syrup. Sprinkle 1 tsp toasted black sesame seeds (once the candy is hardened, sesame seeds won‘t stick to the surface, so do it while candy is soft).
12. Serve on a plate or bowl. Enjoy!

To Make Version 2: Steam & Shallow-Fry

1. Gather all the ingredients.
2. Carefully wash 11 oz Japanese sweet potato (Satsumaimo) (don’t peel the skin).
3. Cut the sweet potatoes diagonally while rotating the sweet potato a quarter between cuts. This Japanese cutting technique is called rangiri.
4. Soak the sweet potatoes in water for 15 minutes to remove the starch.
5. Do not heat the frying pan yet. Add 5 Tbsp sugar, 3 Tbsp neutral oil, ¼ tsp soy sauce, and ¼ tsp rice vinegar (unseasoned) to the pan and combine all together.
6. Dry the sweet potatoes completely with paper towel and place in the pan.
7. Wrap the frying pan’s lid with a kitchen cloth. This is to prevent condensation on the lid dripping into the sweet potatoes while cooking.
8. Cover with the lid and turn on the heat to medium.
9. When you hear bubbling sound from the pan, turn the heat to low to medium low, and set a 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.
10. 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 with 1 tsp toasted black sesame seeds.