Deep fried sweet and sour fish

I don't know much about fish, usually my mom help me to buy fresh fish from my kampung (my hometown is a small fishing village), she help to clean and cut and freeze it for me. The other day when I went back to hometown, my mom told me she managed to buy for me a very fresh and big fish, about 5kg in weight, the fish name in Mandarin is 马友鱼, sorry I don't know the English name, this is the fish image (Latest update-Thanks Pete informed me the English name of this fish, it is called as Threadfin or Kurau in Malay).
Since the fish is too big for my family at one go, I separated into four parts, I use the 1st part (fish body) to cook this yummy sweet and sour fish. Later I will share with you how I cook for the rest of the fish parts.

-Deep fried fish meat, vegetables and sauce. Just eating the deep fried fish meat, also really good, sweet and juicy.

Deep fried sweet and sour fish
(printable recipe)

800 fish meat, cut into cubes
1tbsp light soy sauce
1/2tsp salt
1tsp sesame oil
A dash of white pepper powder

1 green capsicum, cut into wedges
1 yellow capsicum, cut into wedges
1 onion, cut into wedges
1 fresh tomato, cut into wedges
4 cloves of garlic, chopped
4 slices of young ginger

Sauce (combine in a bowl)
5tbsp tomato ketchup
3tbsp vinegar
2tbsp sugar
1tbsp chilli sauce
1tbsp oyster sauce
½ tsp salt or to taste
¼ cup water (or adjust accordingly)

•1/2 tsp corn flour/tapioca flour, mixed with 1 tbsp water for thickening

1. Season fish meat with soy sauce, salt, sesame oil and set aside for 10mins.
2. Coat fish with corn starch/tapioca flour. Deep-fry in hot oil till cooked and crispy. Remove and place on a serving plate.
3. Heat up oil, saute garlic and gingers until fragrant.
4. Add yellow and green capsicums and tomato. Stir-fry briskly. Pour in sauce ingredients and bring to a boil.
5. Add thickening, then add in fried fish and mix well.
6. Dish out and serve hot.

** I can't get good and clear photo especially when I take picture for the dishes that I cooked for dinner, due to the low light condition in the kitchen during evening time. So no choice, I need to use very high ISO (ISO 800) and use the Canon software to do some adjustment, please accept this poor pictures..

Happy Cooking !!