Wash rice 2-3 times until water runs clear.

In a small bowl, add sushi vinegar, sugar and salt. Mix well. You may microwave the mixture for 30 seconds to allow the sugar to dissolve better. Set aside.

In a small pot, add rice and water. Cover with lid and bring to a boil over high heat. Once boiling, stir rice once and reduce to low heat. Cook until rice is tender.

Scoop rice into a bowl and add the vinegar mixture in. Mix well and set aside. Allow rice to cool to around body temperature before moulding into rectangular logs.

Devein prawns using a skewer (without peeling the shells off). Remove the sharp spike at the tail end. Insert skewer into prawns through the belly side to prevent prawns from curling while cooking. Soak in ice water before cooking so that prawns will retain their crunchiness upon cooking.

In a big pot, bring water to a boil. Add prawns in and simmer cook for about 1-2 minutes. Remove prawns and shock in ice water (to prevent them from being overcooked). Remove skewers and prawn shells, leaving the tail intact, then butterfly the prawns from the belly side.

Cut seaweed into small strips (around 1.5cm in width, and 10.5cm in length).

Once rice has cooled to around body temperature, take about 20g of rice and mould into rectangular logs. Tip: Wet your hands with water before moulding so that the rice will not stick to your hands.

Place prawn on top of rice and wrap with seaweed strip. Squeeze about 4g of mentaiko mayo onto each prawn and spread evenly using a knife. Finally, sear with a blowtorch.