Set a large nonstick skillet or well-seasoned cast-iron skillet over medium-high heat and let it warm while you get the sauce and tofu ready.

In a small bowl, stir together the apricot preserves, soy sauce, rice vinegar, and 1/4 cup water until the preserves are mostly dissolved and the sauce looks smooth.

Put the tofu pieces in a medium bowl. Sprinkle 1 tablespoon of the cornstarch over the tofu and toss gently until the pieces are lightly coated on all sides.

Add 2 tablespoons of the oil to the hot skillet and swirl it over the bottom of the pan.

Put the tofu into the skillet in one layer. Cook it without moving it for 4 minutes, until the bottoms look golden brown.

Crisp the tofu: Turn the tofu pieces with tongs or a thin spatula. Cook for 4 to 5 minutes more, turning once or twice, until several sides are browned and the tofu looks firmer and a little crisp.

Transfer the tofu from the skillet to a plate.

Add the remaining 1 tablespoon oil to the same skillet.

Put the red onion and the scallion whites into the skillet. Cook for 2 minutes, stirring often, until the onion starts to soften around the edges.

Add the broccolini to the skillet. Pour in 2 tablespoons water so it can steam briefly, and cook for 3 to 4 minutes, stirring often, until the broccolini is bright green and just tender and the water has mostly cooked away.

Cook the vegetables: Add the garlic and ginger to the skillet. Cook for 30 seconds, stirring, until fragrant.

In a small cup, stir the remaining 1 tablespoon cornstarch with 2 tablespoons water until smooth.