Heat half the oil in a large wok over high heat until smoking. Stir-fry combined sugar snap peas, onions and ginger in 4 separate batches for 3 minutes each until cooked through and crispy. Use a slotted spoon to remove from wok and set aside.
Heat remaining oil in wok until smoking. Stir-fry prawns and sauce for 3 minutes until cooked through.