Cut tofu into 3/4-inch cubes; place in a shallow baking dish. In a small bowl, whisk together soy sauce, rice vinegar, ginger, garlic, sesame oil and crushed red pepper. Pour over tofu. Cover and marinate for 10 minutes. Drain, reserving marinade. In a large skillet, heat 3 teaspoons canola oil over medium-high heat. Add tofu to skillet.