How to Make It
Set the tofu on a paper towel–lined plate. Cover and chill for at least 2 hours or overnight to drain the excess water. Cut the tofu into 1/2-inch cubes or rectangles.
In a food processor, pulse the bread until coarse crumbs form; you should have about 1/3 cup. In a small skillet, heat 2 tablespoons of the oil. Add the bread crumbs and cook over moderate heat, stirring, until golden, 4 to 5 minutes.
In a small bowl, whisk the soy sauce with the vinegar, mirin, sugar, scallion, ginger, garlic and the remaining 1/4 cup of oil until emulsified. Season the vinaigrette with salt and pepper.
Arrange the tomatoes, tofu, basil and onion Caprese-style on a platter. Drizzle some of the vinaigrette on the salad and top with the bread crumbs. Pass the extra vinaigrette at the table.