20 grams sesame seeds (mixture of white and black)
Salt and freshly ground black pepper
200 grams sushi grade tuna fillets
5 tablespoons rapeseed or groundnut oil
6 corn tortillas
A quarter of a white cabbage, finely shredded
1 tablespoon fried red onion or shallots (available from most Asian grocers)
Fresh coriander (cilantro) leaves, finely chopped
To make the seaweed salad, if using, rehydrate the wakame in tepid water for 5-10 minutes. When it's floppy, drain it. Mix it with the remaining salad ingredients. Set aside.
To make the salsa dressing, mix the ingredients together, stirring to dissolve the sugar.
To make the chilli mango salsa, combine the mango, shallot, chilli and coriander, and then pour the salsa dressing over the mango mixture, and stir.
For the tuna filling, pour the sesame seeds onto a plate with salt and pepper and press the tuna fillets down onto them firmly, to coat. Flip over the fillets and do the same on the other side.
To make the taco shells, heat 4 tablespoons of the oil in a heavy-based frying pan (skillet) over a medium-high heat.
Using tongs, place a tortilla in the hot oil. Fry for about 15 seconds, and then flip it over and fold the shell in half, holding it in place with the tongs for about 15 seconds until it's crispy and holding its shape. Drain on kitchen paper, and repeat with the other tortillas. Sprinkle with salt.
To sear the tuna, heat the remaining tablespoon of oil in the frying pan. When it's really hot, cook the tuna for just over 1 minute on each side, for medium-rare, 1 minute longer for well-done.
Remove from the heat, rest for a minute and cut into bite-sized cubes.
If you don't have store-bought crispy fried red onion or shallots for the garnish, heat 2 tablespoons of oil in a frying pan (skillet), and fry a finely sliced shallot until crisp and golden, but not burnt. Drain on kitchen paper and set aside.
To assemble the tacos, place some cabbage in each shell, followed by the seaweed salad (if using), mango salsa, tuna and fried shallots.
Drizzle over some sriracha mayo, garnish with coriander leaves and serve with wedges of lime. Eat immediately with your hands.