Step 1: Press and Prepare the Tofu : Drain the tofu and wrap it in a clean kitchen towel or paper towels. Place a heavy object (like a skillet or can) on top and press for 15–20 minutes to remove excess moisture. Once pressed, cut the tofu into 1-inch cubes.
Step 2: Season and Bake the Tofu : Preheat the oven to 400°F (200°C). In a bowl, toss tofu cubes with soy sauce, oil, and cornstarch until evenly coated. Arrange the tofu in a single layer on a parchment-lined baking sheet. Bake for 25–30 minutes, flipping halfway through, until golden and crispy.
Step 3: Make the Teriyaki Sauce : While tofu bakes, whisk together soy sauce, sugar, vinegar, mirin, garlic, ginger, and water in a small saucepan. Bring to a simmer over medium heat. Stir in the cornstarch slurry and cook until the sauce thickens and becomes glossy (about 2–3 minutes). Remove from heat and set aside.
Step 4: Stir-Fry the Vegetables : Heat sesame oil in a large skillet or wok over medium-high heat. Add onions, bell peppers, and carrots; stir-fry for 3–4 minutes. Add broccoli and snap peas; cook for another 3 minutes, keeping them crisp-tender. Add a splash of soy sauce and toss to combine.
Step 5: Combine Everything : Add the baked tofu to the skillet with vegetables. Pour the teriyaki sauce over and toss gently until everything is evenly coated and heated through.
Step 6: Serve : Serve the teriyaki tofu and vegetables over steamed rice or noodles. Garnish with sesame seeds and green onions.