Herb-Crusted Tuna Loin with Avocado & Baby Lettuces

Serves 4

Ingredients:

One 1 1/2-pound/650-g piece sushi-quality Ahi tuna loin
Salt and freshly ground black pepper
4 teaspoons/20 ml plus 1 tablespoon/15 ml extra virgin olive oil
½ cup coarsely chopped assorted fresh herbs (such as chives, dill, chervil, Italian parsley and tarragon)
2 firm but ripe avocados, pitted, peeled, cut into bite-size cubes
4 tablespoons/55 ml fresh lemon juice
2 tablespoons/10 g thinly sliced fresh chives
½ red jalapeno chili, seeded and finely chopped (optional)
4 cups (lightly packed)/75 g mixed baby lettuce leaves
Additional extra virgin olive oil, for drizzling

Method:

To prepare the tuna:

Trim the tuna loin into a round shape discarding the sinewy flat side of the loin. Heat a nonstick griddle pan over high heat until it is very hot. Sprinkle the tuna loin with salt and pepper then coat it with 2 teaspoons/10 ml of the oil.

Place the tuna on the hot pan and cook for approximately 1 minute on each side, turning to sear all the sides except the ends, or until just the outer ¼ inch/.6 cm of the tuna is cooked and golden brown (the tuna should still be raw). 

Remove the tuna from the pan and place it on a plate to cool completely. Sprinkle the assorted fresh herb mixture on the work surface. Coat the seared sides of the tuna with 2 teaspoons/10 ml of oil.  Roll the seared sides of the tuna in the herbs to coat, patting the herbs so that they adhere to the tuna.

Wrap the tuna with plastic wrap, forming a tight cylinder shape. Refrigerate for at least one hour and up to 6 hours. This will allow enough time for the herbs to flavor the tuna.

To prepare the salads:

Toss the avocado cubes, 3 tablespoons/40 ml of lemon juice, 2 tablespoons/10 g of chives and the chili in a medium bowl. Season the avocado mixture to taste with salt and black pepper.

Toss the baby lettuces in a large bowl with the remaining 1 tablespoon/15 ml of lemon juice and 1 tablespoon/15 ml of oil. Season the lettuce leaves to taste with salt and pepper.

To assemble and serve:

Place a small mound of the lettuce leaves on one end of each plate. Using a large very sharp knife, thinly slice the tuna crosswise forming ¼-inch/.6-cm-thick rounds. Lay one slice of tuna slightly offset atop the lettuce mound on each plate. Sprinkle the tuna lightly with salt and drizzle with the olive oil.
Spoon some of the avocado mixture over the tuna slices. Repeat with the remaining lettuces, tuna and avocado mixture, drizzling each slice of tuna with oil and sprinkling it with salt, and ending with the tuna.