Place tofu on large plate. Cover with second plate and weigh down with 2 large, heavy cans. Let stand for 10 minutes; drain. Cut in half horizontally.
Meanwhile, in shallow baking dish large enough to hold tofu in single layer, whisk together soy and hoisin sauces, garlic, sesame oil and hot sauce. Add tofu; turn to coat. Bake in 350°F (180°C) oven, turning once, until golden, about 30 minutes.
Meanwhile, brush large nonstick skillet with olive oil; heat over medium-high heat. Sauté mushrooms, green onion and ginger until golden, about 5 minutes. Cut bok choy in half lengthwise and add to skillet along with red peppers; heat. Cover and steam until bok choy is tender-crisp, about 4 minutes.
Cut each piece of tofu in half diagonally. Arrange on warmed plates and serve with bok choy mixture.