Wash all vegetables. Cut broccoli into bite-size florets. Core and slice the red and yellow bell peppers into 1/2-inch strips. Peel and slice carrots on the diagonal into 1/8- to 1/4-inch thick slices. Halve the zucchini lengthwise, then slice into 1/4-inch half-moons. Clean mushrooms and slice thickly.

Prepare tofu (if using)

Press tofu for 15–20 minutes to remove excess water, then cut into 3/4- to 1-inch cubes. Pat dry with paper towels. Optional: toss tofu cubes with 1/2 tsp soy sauce and 1 tsp cornstarch to help them crisp.

Blanch broccoli (optional for bright color)

Bring a medium pot of salted water to a boil. Add broccoli florets and cook 1 minute until bright green and slightly tender. Immediately drain and transfer to an ice bath or rinse under cold water to stop cooking. Drain well.

Sauce & Seasoning

Make sauce

In a small bowl, whisk together soy sauce, rice vinegar, honey (or maple), grated ginger, minced garlic, sesame oil, 1 tsp cornstarch, and 2 tbs water until smooth. Add red pepper flakes if using. Taste and adjust: add up to 1/2 tsp more soy for saltiness or another 1/2 tbs sweetener if you prefer sweeter.

Cooking & Finishing

Heat a large skillet or wok over medium-high heat until very hot. Add 1 tbs neutral oil and swirl. If using tofu, add cubes in a single layer and let them sear 2–3 minutes without moving, then turn to brown on another side for a total of 6–8 minutes until golden on most sides. Remove tofu and set aside.

Add remaining 1 tbs neutral oil to the hot pan. Add carrots and stir-fry 1–2 minutes. Add bell peppers and mushrooms and stir-fry another 1–2 minutes. Add zucchini and blanched broccoli and stir-fry 1–2 minutes until vegetables are just tender-crisp. Season with 1/4 tsp salt and a few grinds of black pepper while cooking.

Return tofu to the pan (if using). Give the prepared sauce a quick stir (cornstarch may settle) and pour it over the vegetables and tofu. Stir continuously as the sauce comes to a simmer — the cornstarch will thicken in 30–60 seconds and coat everything. Cook 1 more minute to meld flavors; if sauce becomes too thick, add 1–2 tbs water to loosen.

Turn off heat. Stir in sliced green onions and sesame seeds. Taste and adjust seasoning: add a pinch of salt, a splash of soy, or a squeeze of lime/lemon if desired.

Transfer to a serving platter or bowls and serve immediately over rice, noodles, or grain of choice. Garnish with extra green onion and sesame seeds, and lime/lemon wedges on the side.