Slice the tofu in half crosswise. Slice each half once on the diagonal, lay cut side down, and cut each vertically into 3 slices, to make 12 triangles. Arrange the slices on double-thick layers of paper towels and press to remove as much moisture as possible. Repeat as necessary to dry the tofu well.
3
In a shallow dish, lightly beat the eggs with the remaining 3 tablespoons hoisin sauce and 1 tablespoon vinegar, 2 teaspoons of the sesame oil, and 1/2 teaspoon salt. Put the panko and cornstarch in separate shallow bowls. Lightly season the tofu on both sides with salt. Dredge each piece of tofu in the cornstarch, shaking off the excess, then in the egg mixture, and then in the panko, setting the triangles on a plate as you finish each one.
4
Heat 1/4 cup of the peanut oil in a 12-inch nonstick skillet over medium-high heat. When the oil begins to shimmer, add half of the tofu triangles and cook, turning once, until golden and crisp, about 2 minutes per side. Transfer to a paper-towel-lined plate, and season lightly with sea salt. Repeat with the remaining tofu.
