Things You'll Need: Measuring spoons, 5 zipper plastic sandwich bags, 1 oz. lagniappe water, 4 large cloves of garlic (cut in half), Zatarain's Garlic and Onion Liquid Shrimp and Crab Boil, 3 bay leaves, measuring cup, 2 lemons, 5 oz. salt, ice, large pot, 5 lbs. large shrimp (2 to 3 oz.), cayenne pepper to taste, 1/2 stick butter (4 tbsp.). Step 1: Fill the pot 2/3 of the way full with water and place it on the stove. Step 2: Turn the heat on the stove up to the highest level. Step 3: Rinse and cut the lemons in half. Step 4: Add the cayenne pepper, lagniappe, garlic, butter, bay leaves, salt and the proper amount of Zatarain's liquid as listed on the label. Step 5: Squeeze the lemon juice from the lemons into the pot and then drop the lemons into the pot. Step 6: Bring the water to a boil. Step 7: Pack ice into the zipper sandwich bags and place the ice back into the freezer while you wait for the water to boil. Step 8: Add the shrimp to the boiling pot and set a timer for 3 minutes. Step 9: Get the ice packages out of the freezer. Step 10: Turn off the heat when 3 minutes of boiling has occurred for the shrimp. Step 11: Place the ice bags on top of the cajun boiled shrimp to quickly cool down the shrimp and allow the shrimp to soak up the flavors in the pot. Leave the ice in the bags so you don't water down the flavor in the pot. Step 12: Wait for the shrimp to soak up the flavor for 5 to 10 minutes depending on how hot and flavorful you want the shrimp to be. Step 13: Strain the shrimp from the pot and serve.