Press the tofu: Wrap the tofu in a clean kitchen towel and place something heavy on top for 10–15 minutes. This helps remove excess moisture so it crisps nicely.
Mix the sauce: In a small bowl, whisk soy sauce, rice vinegar, sesame oil, maple syrup, water, cornstarch, and optional heat. Set aside.
Prep the vegetables: Slice all vegetables into bite-sized pieces.
Keep the garlic, ginger, and green onion whites separate from the rest.
Cube and coat tofu: Cut the pressed tofu into 3/4-inch cubes. Toss gently with 1 tablespoon cornstarch until lightly coated.
Sear the tofu: Heat 1 tablespoon oil in a large skillet or wok over medium-high heat. Add tofu in a single layer and cook 6–8 minutes, turning occasionally, until golden on most sides.
Remove to a plate.
Sauté aromatics: Add the remaining 1 tablespoon oil to the pan. Add garlic, ginger, and green onion whites. Stir for 30 seconds until fragrant.
Stir-fry the vegetables: Add broccoli and carrots first.
Cook 2 minutes, stirring often. Add bell pepper, zucchini, and peas. Cook 2–3 minutes more until crisp-tender.
Add tofu and sauce: Return tofu to the pan.
Give the sauce a quick stir (cornstarch settles), then pour it in. Toss to coat and cook 1–2 minutes until the sauce turns glossy and lightly thickens.
Finish and serve: Remove from heat. Add green onion tops.
Taste and adjust seasoning with a splash more soy sauce, vinegar, or lime. Sprinkle sesame seeds if you like. Serve over warm rice or noodles.