Drain the tofu and press between layers of paper or kitchen towels to remove excess liquid. Repeat the process once more, and cut it into ¾-inch slices.
On a large plate, combine the cornstarch and salt. Dredge the tofu in the mixture to coat. Set aside.
Heat the oil in a large nonstick skillet over medium-high heat. The oil is ready when a pinch of bread crumbs bubbles immediately. Carefully add the tofu slices one by one so the oil doesn’t splash. Cook until crisp and brown, 3 to 4 minutes. Carefully flip and repeat on the opposite side. Reduce the heat to medium-low and remove the tofu from the skillet. Place the tofu on a plate covered with a few layers of paper or kitchen towels to drain. Discard remaining oil from the skillet.
Coarsely crush the peppercorns with a mortar and pestle or place in a resealable plastic bag and crush with a small saucepan. The consistency should be coarser than ground pepper.
In a medium bowl, combine the plum jam, soy sauce, vinegar, honey, ginger, the crushed peppercorns, and ¼ cup (60 ml) water. Transfer to the cooled skillet and bring to a boil. Add the tofu and cook, basting the tofu occasionally, until the sauce is thick enough to coat a spoon, about 3 minutes. To serve, divide among plates and top with more crushed peppercorns.