In a large pot, combine 2500 ml water, 2 tbs coarse sea salt, 1 tbs black peppercorns, 2 bay leaves and the halved fresh lemon. Bring to a rolling simmer over medium-high heat.

Prepare ice bath

While the liquid heats, fill a large bowl with ice and cold water (about 1000 g ice). Set aside near the stove for quick transfer.

Poach prawns

Once the poaching liquid reaches a gentle simmer (not a hard boil), reduce heat so the surface is barely moving. Add the tiger prawns in a single layer and cook just until the shells turn pink-orange and the flesh is opaque — about 2 to 3 minutes for large prawns. Do not overcook.

Shock prawns

Immediately remove prawns with a slotted spoon or spider and transfer them to the prepared ice bath to stop cooking. Leave in the ice bath for 3 to 5 minutes until fully chilled.

Peel and chill

If serving peeled, remove shells leaving tails on if desired (or fully peel). Pat prawns dry on paper towels, arrange on a serving platter over a bed of ice or chilled plates, and keep refrigerated until ready to serve (up to 2 hours). Reserve about 24 prawns for service.

Housemade Cocktail Sauce

In a medium bowl, combine 1 cup ketchup, 3 tbs prepared horseradish (increase with the optional extra 1 tbs if you prefer more heat), 2 tbs fresh lemon juice, 1 tsp Worcestershire sauce, 1 tsp hot sauce, 1 tsp smoked paprika, 0.5 tsp salt, and 0.25 tsp freshly ground black pepper.

Whisk thoroughly until smooth. Taste and adjust balance: add more horseradish or hot sauce for heat, more lemon juice for brightness, or a pinch of sugar if the tomato is too acidic.

Cover and chill the sauce for at least 15 minutes to let flavors meld. Keep refrigerated until ready to serve.

To Serve

Arrange chilled prawns on a platter over crushed ice or a chilled serving tray. Place a small bowl of cocktail sauce in the center or several small ramekins around the platter.

Garnish with lemon wedges and sprinkle chopped parsley over the platter if using. Provide cocktail picks so guests can spear prawns easily.

Serve immediately, keeping the platter on ice or chilled surface. Leftover prawns and sauce should be refrigerated and consumed within 24 hours.