1 tablespoon plus 2 teaspoons thinly sliced fresh coriander
3/4 teaspoon wasabi powder
1/2 teaspoon toasted sesame seeds
1 teaspoon finely diced scallion (from white and light green parts only)
2 teaspoons fresh lemon juice, plus 1/2 lemon
Fine salt to taste
Freshly ground white pepper to taste
1 ripe tomato, peeled, seeded and cut into 1/8-inch dice.
20 best quality potato chips
Special equipment: round mold or open-ended cookie cutter, 2 1/4-inches in diameter and 1½ inches high.
Combine the ginger and corn oil in a small bowl, cover and refrigerate overnight. Strain.
Trim any blood or pieces of nerve from the tuna. Cut into tiny dice (no bigger than 1/8 inch). Put the tuna in a mixing bowl. The recipe can be made to this point up to five hours ahead; cover and refrigerate the tuna.
No more that 15 minutes before serving, add 1 tablespoon of coriander to the tuna, along with the jalapeno, wasabi, sesame seeds, scallion, 2 tablespoons of lemon juice and 4 teaspoons of the ginger oil, Mix gently. Season with salt and pepper. Place the mold in the center of the salad plate. Fill the mold with the mixture, pressing it gently so the tuna is even and compact. Lift off the mold, Repeat, making 3 more plates.
Drizzle the remaining oil on the plates around the tartare. Sprinkle the tomato over the oil, then sprinkle the remaining coriander over the tomato. Squeeze a little lemon juice over the garnish. Stand 5 potato chips up on their sides in each tartare, arranging them in circle. Serve immediately.