1Place all ingredients except the prawns or shrimp in a medium saucepan with a tightfitting lid. Bring to a boil over medium-high heat, stirring until sugar and salt are dissolved, about 4 minutes. Add prawns, stir to incorporate (making sure the prawns are submerged), cover, and remove from heat. Let sit until prawns are just cooked through (they will turn orange in color and look opaque), about 15 minutes.
2Remove prawns from the pickling liquid and refrigerate in a container with a tightfitting lid until chilled. If you desire, reserve the pickling liquid for our Bloody Mary with Pickled Prawns.