Step 1

In a bowl, combine the corn oil and ginger and let stand at room temperature for at least 2 hours. Strain the oil.

Step 2

With a very sharp knife, cut the tuna into 1/8-inch dice. In a large bowl, combine the tuna with 3 tablespoons of the ginger oil, 3 tablespoons of the cilantro and the jalapeño, wasabi, sesame seeds, scallion and lemon juice. Mix gently and season with salt and pepper.

Step 3

Stand a 1 1/2-inch-tall and 2 1/4-inch-round mold or a biscuit cutter in the center of a salad plate. Fill the mold with tuna tartare, pressing gently. Lift off the mold. Repeat with the remaining tartare.

Step 4

Drizzle the remaining ginger oil around each tartare and sprinkle with the tomato, the remaining tablespoon of cilantro and a squeeze of lemon juice. Stand 5 potato chips in a circular pattern in each tartare and serve immediately.