1. Press the tofu: Wrap the tofu block in a clean kitchen towel or paper towels and place a small cutting board or plate on top. Weigh it down with a can or skillet and let it sit for 10–15 minutes to remove excess moisture, then cut into bite-sized cubes.

2. Sear the tofu: Heat 1 tablespoon of oil in a large nonstick skillet or wok over medium-high heat. Add the tofu cubes in a single layer and cook, turning occasionally, until all sides are golden and lightly crisp, about 8–10 minutes total. Transfer the tofu to a plate and set aside.

3. Cook the vegetables: In the same pan, add the remaining 1 tablespoon of oil. Add the sliced onion and cook for 2–3 minutes until it begins to soften. Add the mushrooms and cook until they release their moisture and start to brown, about 4–5 minutes. Stir in the broccoli florets and cook for another 3–4 minutes, until crisp-tender.

4. Make the sauce: While the vegetables cook, whisk together the soy sauce, water or broth, rice vinegar, brown sugar or maple syrup, minced garlic, sesame oil, and cornstarch in a small bowl until smooth and no lumps remain.

5. Combine tofu, vegetables, and sauce: Return the tofu to the skillet with the vegetables. Give the sauce a quick stir and pour it into the pan. Cook, stirring frequently, until the sauce comes to a simmer and thickens, coating the tofu and vegetables in a glossy glaze, 2–3 minutes. If the sauce becomes too thick, add a splash more water to loosen it.

6. Garnish and serve: Taste and adjust seasoning with extra soy sauce, vinegar, or a pinch of sugar if needed. Remove from the heat and sprinkle with sesame seeds and chopped cilantro. Serve hot over cooked rice or noodles.