If I could aford it, I Probably would be eating tuna more often than just when no one else is looking.

Seared sesame tuna steak

Ingredients

Tuna steaks (about 160g per person)
3 1/2 tablespoons soy sauce
3 tablespoons sesame seeds
1 1/2 tablespoons peanut oil, plus extra to fry
2 handfuls of rocket or baby spinach leaves
1 small Spanish red onion, cut into rings
1 1/2 tablespoons sherry vinegar
1 teaspoon sesame oil

Method

Cover the tuna in two tablespoons soy sauce. Press sesame seeds into both sides of fish and refrigerate for 1/2 hour.
Heat a little peanut oil in a pan over very high heat and fry tuna quickly on one side for about 1 minute, then turn and cook for about half a minute. Set aside to rest.
Meanwhile, combine remaining ingredients and transfer to a serving plate.