Preparing the Tuna:

1. Place the tuna filet on the chopping board lengthways. Starting at the farthest end, begin making slices of approximately 0.5 cm to 1 cm in thickness. Make the slices slightly thicker if the filet is particularly tender, as this will prevent them from falling apart. For the cleanest possible cut, bring the heel of the knife down and through the tuna. Cut approximately six slices from the block, and set those aside.
2. Drizzle the remaining ‘block’ of tuna with sesame seed oil, turning it over to ensure even coverage on all sides. Use your fingers to rub the oil into the tuna on the four longest sides.
3. Sprinkle a generous helping of dried and chopped coriander leaves over the tuna filet – covering the entire surface area. Repeat this step for all four oiled sides.
4. Once the filet block is entirely covered, transfer it to a medium hot frying pan using the blade of your knife. Sear each side for no more than 10-15 seconds, until the fish is visibly white on the outside. Transfer the tuna block back to the chopping board, ensuring it sits on a raw edge to cool. This will allow the heat to escape the fish, without it cooking further.

Arranging the Garnish:

1. Using your fingers, form a handful of shredded carrot into a small ball. Position the ball to the right and rear of the sushi board.
2. Fan out the cucumber lengths on your chopping board. Trim off any excess at the ends, so that they are all of equal length. Using your knife, transfer all four slices together to the sushi board, positioning them so that they lean against, and overlap the carrot ball.
3. Using the blade of your knife, position a salmon slice vertically at the base of the chopping board. Transfer a second piece over, arranging it above the first so that it overlaps. Repeat with the remaining slices to create one long length of overlapping salmon slices. Starting at the end closest to you, begin loosely rolling the salmon slices into a rosette. Once you reach the end, use your fingers to apply a little pressure to both sides. Keep your fingers in place while using your other hand to lift it over to the sushi board. Set the rosette down at the opposite end of the board.
4. Form another small, decorative ball with the grated radish. Position the ball at the farthest end of the cucumber strips – next to the carrot ball.
5. Fan out the seared tuna slices. Then, use your knife to transfer over to the sushi board. Lay the slices on top of the cucumber lengths at a sloping angle.
6. Place half a lemon on your chopping board. Position your knife at a 45-degree angle from the center, and begin making wafer thin slices. You will need 10-15 for the garnish. Standing the slices up with your fingers, spread them out in a straight line, allowing each to slightly overlap the next.Transfer the lemon slices intact to the chopping board, and arrange them against the seared tuna slices. Spread the slices out so that they curve around the prepared garnish.
7. Create a green bed behind the lemon slices with the two lettuce leaves. Atop these, add the grated cucumber ball. The remaining, uncooked tuna slices may then be arranged to cascade down from the cucumber garnish.
8. Spread out the avocado slices on the flat of your knife. Gently turn the knife so that the spine lifts the avocado. Use your fingers at the same time to manipulate the avocado into a cone shape. Position on its side in front of the lemon slices on your sushi board, then add a teaspoon of black caviar to the mouth of the cone.
9. Add a small ball of pickled ginger to the space between the lemon and tuna slices.
10. Though optional, laying a few chive strips atop the uncooked sashimi slices is a great finishing touch, as it helps them blend in with the organic esthetic.

Serving Suggestion:

Add a small ramekin of Soy Sauce and/ or Wasabi to your presentation so that guests can help themselves.