2) Remove the tuna to a plate – it should be seared on the outside and raw inside. Allow to cool and then cut into cubes.
3) Whisk together 30ml of olive oil, the lime zest, lime juice, wasabi powder, soy sauce, tabasco, 2 tsp salt and 1 tsp pepper in a small bowl. Toss the avocado in the dressing and then add the tuna, red onion, spring onion and sesame seeds.
4) Line the inside of the toasted rolls with rocket leaves, fill with the tuna mixture, and serve.
Cook's Note: If you don't want to heat a barbeque, you can sear the tuna in a dry saute pan over a high heat. Heat the pan for 2 minutes, add the tuna steaks and cook for 1 1/2 to 2 minutes on each side until seared on the outside and still raw inside.