1. Add all the ingredient A into a medium bowl and add the chicken to marinate at least 2 hours (or even overnight) in the fridge.
2. *Making Sauce :* In a bowl, add all the sauce ingredients and mix. Let is sit in the fridge until use.
3. Add flour and katakuriko/potato starch in a plate and roll the chicken pieces in it until coated.
4. Heat 2 to 3 cm vegetable oil in a large saucepan over medium heat. Carefully add 2 or 3 chicken pieces (depending on your saucepan's size) and deep-fry them, turning occasionally, until crisp and cooked through. Transfer them to a plate lined with paper towels to drain the excess oil. Continue with the rest of the chicken.
5. Toast the cut side of the burger buns lightly, and spread the sauce on the bottom half of the bun. Then place lettuce (or shredded cabbage), chicken. Add more sauce if you like. Cover with the top side bun.
1. In a frying-pan, heat 1 tbsp oil and fry garlic until fragrant. Add vegetables and continue stir frying until wilted. Add salt and butter to season. Let it cool to room temperature.
2. Transfer the vegetable in a medium bowl and add all ingredient A. Knead mixture with hands thoroughly until the mixture forms sticky and moist.
3. Take a small portion of the mixture, and shape it into a flat, round disc shape, and then put a piece of mozzarella on it. Fold the meat mixture over it and make it into a round ball. Coat the balls lightly with katakuriko/potato starch. Repeat until all of the meat mixture is used.
4. In a skillet, heat 2 tbsp vegetable oil over medium-high heat and place the patties. Fry them on both sides until nicely brown. Reduce the heat to low and simmer for about 15 to 20 minutes with lid on.
5. Move the cooked patties to a plate. Add all the sauce ingredient to the skillet (don't wash it) and bring it to a boil over medium-high heat. Reduce the heat to low and place the patties back onto the sauce and coat both sides with the sauce. Cover and let them cook over low heat for about 3 min.