Before beginning, press the tofu in a tofu press, or wrap in paper towels and place under a heavy object for 30 minutes to remove excess moisture.
Combine all of the sauce ingredients and set aside.
Cut the tofu into ~¾” cubes. Dust the tofu with about ¼ cup of cornstarch and toss to fully coat.
Heat a generous swirl of veggie oil over medium-high heat in a wok or large skillet. Add the cubed tofu pieces. Cook, tossing occasionally, until the tofu is golden and crispy on most sides, about 10 minutes. Once cooked, remove to a plate.
Reduce the heat to medium, add a little bit more oil and the broccoli and cook, stirring frequently, until the broccoli has brightened in color and is just starting to char, about 3 minutes. Remove the broccoli to a plate.
Add a little more oil to the skillet if needed, then add the garlic and the whites of the green onion. If you want to add some spice, add a few crushed red pepper flakes now as well. Cook until fragrant, about 1 minute, stirring constantly. Add the sauce and mix everything together, let it come to a boil then remove the skillet from heat.
Add the tofu pieces and toss until they're fully coated in the sauce. Then add the broccoli and toss further (the broccoli will not get covered in as much sauce as the tofu). Serve immediately over a bed of white rice (I use jasmine), and top with green onion greens, sesame seeds, and red pepper flakes (optional).
Notes
If you make a double batch, do not overcrowd the tofu in one pan. Use two pans, or cook the tofu in two batches.