I have done a version of this before – except I used sesame oil and sesame seeds instead. The herbs really give it a freshness to it.. and if only pictures could portray the smell of the herbs when you are cutting them!! Easy to make, and not time consuming at all. A great appetizer to make a head of time.
Handful of Italian Parsley
Handful of Chives
Drizzle oil on a piece of aluminum foil and spread with a basting brush. Chop the parsley and the chives and spread over the oiled surface. Season the tuna with pepper, and place the steak on the herbed surface. Roll the foil like a Christmas cracker. Chill in the fridge for 20 minutes.
Heat a cast-iron skillet on high heat. Sear each side of the tuna steak for 25-30 seconds. Let cool and place back in the fridge for 30 minutes – up to 4 hours.
Remove from foil and slice thin slices. Arrange on the plate and drizzle with sesame oil.
Source: Gordon Ramsay