Marinade the duck breast with BBQ marinade and vacuum-seal it. Cook it in the sous-vide at 55 °C for 3 hours. Leave the duck breast to cool thoroughly. Cook the sushi rice in the water for 10 minutes, turn off the heat and leave it for another 15 minutes in a covered pan. Bring the rice vinegar, sugar, ginger and salt to the boil and stir it into the cooled sushi rice. Mix the mayonnaise with the Thai curry. Arrange the sushi rice on the sheets of nori and build it up with the duck. Roll it up tightly and leave it to rest in the fridge. Roll the rolls in the egg white and dip them in the panko. Fry the rolls at 175 ⁰C until they are golden brown. Cut them into nice, evenly-sized sushi and garnish with the Thai curry mayonnaise, suitable cress and marinated, halved tomatoes.