Combine all sweet and sour sauce ingredients ; water, cooking sake, apple cider vinegar, black rice vinegar, cane sugar, soy sauce and ketchup. Stir well until the sugar is dissolved. Leave it until you use.

Cut green bell pepper and red bell pepper in half and get rid of the seeds. Cut them into bite-size pieces. Cut a onion into bite-size pieces. Put the green bell pepper in a bowl and red bell pepper and onion in the another bowl. Set aside.

Combine all marinade ingredients, grated ginger, soy sauce, cooking sake, cane sugar, sesame oil. Set aside. Pat the pork dry with paper towel. Pare away excess fat from the pork.

Cut the pork into thick slices. Poke holes into each slice with fork. Pound each slice lightly with the back of the knife.

Cut the pork into bite-size chunks. Mix the pork with the marinade.

Heat the oil for frying in a frying pan over medium high heat. Toss the pork in the potato starch to coat. Deep fry the pork over medium heat (170℃, 338F) for 4-5 mins until evenly browned or crisp. Drain excess oil.

Deep fry the green bell pepper over medium heat for 30 sec. Deep fry red bell pepper and onion over medium heat for a min. Drain the oil on paper towels.

Mix 1 Tbsp potato starch and 1 Tbsp water ; set aside. Pour the sweet and sour sauce in a large pot and heat it. When the sauce boils, stir the potato starch and water mixture until smooth. Turn off the heat and add the mixture to the sauce while stirring the sauce. Stir it well until smooth.

Put the fried vegetables and pork in and mix roughly. Heat it over medium heat for 3 mins and bring to a boil while mixing the bottom sometimes to prevent scorching. Turn off the heat and add 1/2 Tbsp sesame oil and mix roughly (in the video of youtube, it completely slipped my mind). It's all done!