Three 15-ounce packages firm tofu, drained and halved horizontally
4 scallions, white and light green parts only, thinly sliced
Two 10-ounce bags spinach, washed
1 teaspoon cornstarch mixed with 1 tablespoon water
In a small bowl, whisk the soy sauce with the honey, sherry, ginger, garlic and sesame oil. Place 3 of the tofu halves in a glass pie plate and spoon half of the soy mixture on top. Sprinkle with half of the scallions and top with the remaining tofu halves. Pour the remaining soy mixture over the tofu and scatter the remaining scallions on top.
Pour 1 inch of water into a wide, deep skillet and bring to a boil. Place the spinach in a steamer basket and put the basket in the skillet. Cover and steam the spinach just until wilted, about 3 minutes. Drain the spinach very well, then transfer it to a large plate; cover with foil.
Place a ramekin or biscuit cutter in the center of the skillet. Set the pie plate with the tofu on the ramekin, cover and steam until the tofu is hot, about 10 minutes. Arrange the tofu around the spinach, cover and keep warm. Pour the tofu sauce into a saucepan and bring to a simmer. Stir in the cornstarch mixture and cook over moderate heat, stirring occasionally until thickened, about 3 minutes. Pour the sauce over the tofu and serve.