Clean, wash and cut the spring onions in half crosswise. Shrimps wash, dab dry and season with salt and pepper. Heat oil in a pan and fry the prawns in it for about 5 minutes on both sides. Add spring onions and fry for about 1 minute. Season with salt and pepper. Remove the prawns and spring onions and arrange them on plates with the sprouts. Drizzle with sweet and sour sauce