ปลาดอลลี่ผัดพริกหยวก ( Stir-fried Dolly Fish with Bell Peppers )

Ingredients:
300 grams Dolly fish ,
60 grams Bell pepper ,
10 grams Spring onion ,
60 grams Onion ,
2.5 tablespoons oyster sauce ,
1 tablespoon seasoning sauce ,
1/2 tablespoon sugar ,
1/2 tablespoon dark soy sauce ,
2 tablespoons water ,
Oil