Slice the onion thinly, julienne the carrot, and slice the bell peppers after removing stems and seeds.

Pat the salmon fillets dry with a paper towel, season both sides with salt and pepper, and coat with potato starch.

Heat 1 tbsp of vegetable oil in a pan, place the salmon skin-side down, and fry on medium heat until golden. Flip, cover, and cook on low heat for 3 minutes until cooked through. Remove from the pan.

Wipe the pan clean, add 1/2 tbsp of vegetable oil, and stir-fry the onion, carrot, and bell peppers on medium heat until softened. Add the sweet and sour sauce ingredients and bring to a boil. Stir in the thickening agent and cook until the sauce thickens.