Cut tofu into triangles, then coat all sides with cornstarch.
Whisk the rest of the glaze ingredients in small bowl.
Heat 3 tablespoons vegetable oil in 12-inch nonstick skillet over medium-high heat until shimmering.
When skillet is hot, add tofu in single layer and cook until golden brown, 4 to 6 minutes. Turn tofu with tongs and cook until second side is browned, 4 to 6 minutes more.
Add glaze ingredients and cook, stirring, until glaze is thick and tofu is coated, 1 to 2 minutes.
