Add half of a lemon, sliced or cut in chunks, 1-2 teaspoons Old Bay seasoning, 1 minced garlic clove, and 1 teaspoon of salt. Let this mixture boil for 1 minute before adding the prawns. Leave the tails on, and make sure they are covered in water. Simmer for approximately 3 minutes or until the prawns turn pink. Remove from heat. You can leave the shells and head on, or remove them before cooking. Leaving them on will lead to a stronger flavor. As soon as they come off, drain the hot water and plunge the prawns in a cold water keep them from cooking. You can use that water as the base of a soup stock if you want to save it. These prawns are a nice addition to a buffet table, often placed on a large platter and served with a variety of sauces, such as cocktail sauce, tartar sauce or drawn butter. These prawns also work well in a prawn salad with a mayonnaise-based dressing, either served on a bed of greens or in a bread roll.

TL;DR in Vietnamese:
Đun lượng nước vừa đủ để làm ngập toàn bộ tôm. Cho tôm vào nồi và giảm lửa. Ngâm tôm vào bát nước đá để tôm không tiếp tục chín. Thưởng thức món tôm được làm lạnh.