Season prawns/ shrimp with salt and pepper.
In a shallow dish mix together the flour and cornstarch.
In a separate shallow dish add eggs and whisk.
Dredge each prawn in the flour mixture, then dip in the whisked egg, then again coat in the flour mixture.
In a wok or pan, heat oil over medium high heat. Once it reaches 350°F (177°C), add the battered shrimp and fry until golden brown, about 4-5 minutes. Work in batches not to overcrowd the pan. Transfer to a plate. Fry the next batch.
Discard the oil from wok and carefully wipe the inside of the pan with paper towels.
Add 1 tablespoon oil and heat the wok over medium-high heat.
Once it is hot, add the garlic and onions, stir fry for 30 seconds.
Add the peppers and cook further for 1 minute.
Add in the pineapple and stir fry for 1 minute.
Add the prawn and the sweet and sour sauce, stir to coat and cook for 1-2 minutes.
Garnish with green onions and sesame seeds.
Serve over steamed rice.
Enjoy!