Shell, devein, and butterfly shrimp. Combine shrimp and marinade ingredients; stir to coat. Let stand 10 minutes. Combine seasoning ingredients; set aside.
Place a wok over high heat until hot. Add 2 tbsp oil, swirling to coat sides. Add prawns and stir-fry for 1 to 2 minutes. Remove prawns to a bowl and set aside.
Add remaining 1 tbsp oil to wok, swirling to coat sides, over high heat. Add chillies and bell pepper; stir-fry until fragrant, about 10 seconds. Add shrimp, lychees, and seasonings; cook until heated through.