Preheat the oven to 375°F.
In a bowl whisk together the soy sauce, vinegar, oil, honey, ginger, and garlic. Place the mushrooms in a bowl and add enough of the marinade to evenly coat them. Toss to combine.
Arrange the tofu in a single layer in a small baking dish. Pour the remaining marinade over the tofu.
Transfer the tofu to the oven and roast for 20 minutes. Spread the mushrooms out on one or two baking sheets and transfer to the oven. Continue roasting the tofu and the mushrooms until the tofu is nearly dry and well browned and the mushrooms are tender and golden, about 10 to 15 minutes.
Arrange the spinach on serving plates. Drizzle with some of the remaining marinade from the tofu pan. Divide the tofu slices among the plates and top with some of the mushrooms. Serve.