Toast 2 tbsp of black sesame seed in a dry pan. Crumble or cut 6 leaves of nori (mine were 5x7 cm) and mix with 2 tsp of sea salt and the sesame seeds.
Cover both sides of a piece (250 gr) of fresh tuna with the mix and press. Put the tuna in the fridge for about an hour.
In the meantime peel a 6 cm piece of rettich (daikon, or white radish) and cut into matchsticks.
Mix 3 tbsp of Mirin, 2 tbsp of lemon juice and 2 tsp of horseradish to make a dressing.
Cut the tuna, serve with the rettich, the small leaves of celery.
Pour the dressing over in and add a bit of sushi ginger,
<Christmassy with a few mini tomatoes?
(inspired by Donna Hay)