Press the tofu: Wrap the tofu block in a clean kitchen towel and place a heavy pan on top for 10–15 minutes. This helps it crisp up.
Make the sauce: In a bowl, whisk soy sauce, hoisin, rice vinegar, sesame oil, sriracha, brown sugar, water, and cornstarch until smooth.
Set aside.
Prep the tofu: Cut pressed tofu into 1-inch cubes. Toss gently with 2 tablespoons cornstarch until coated.
Crisp the tofu: Heat 1 tablespoon oil in a large skillet or wok over medium-high heat. Add tofu and cook 7–9 minutes, turning occasionally, until golden and crisp on most sides.
Transfer to a plate.
Start the veggies: Add the remaining 1 tablespoon oil to the pan. Add broccoli and carrots first. Stir-fry 2 minutes.
Layer in more veg: Add bell pepper, zucchini, and snap peas.
Stir-fry another 3–4 minutes until crisp-tender.
Aromatics: Push veggies to the sides. Add garlic, ginger, and green onion whites to the center. Cook 30 seconds until fragrant.
Sauce it up: Return tofu to the pan.
Whisk the sauce again (cornstarch settles), then pour it in. Toss everything and cook 1–2 minutes until the sauce thickens and coats.
Finish and serve: Remove from heat. Top with green onion greens and sesame seeds.
Serve over rice or noodles with a squeeze of lime.