Defrost the Tuna steaks as described below.
Cook the rice. Finely chop the red onion and hazelnuts. Thinly slice the radish.
Sear the tuna steaks at high heat for 1 minute on each side. Add salt and pepper.
Immediately serve the semi-cooked steaks with rice and radishes. Sprinkle with hazelnuts and red onion, and then sprinkle with hazelnut oil.