Cut the tofu into 6 slabs crosswise. Blot well on paper towels or clean tea towels (or use the a tofu press ahead of time for making the tofu nice and firm), then cut into dice.
Heat the oil in a large skillet or steep-sided stir-fry pan. Add the tofu and and sauté over medium-high heat until golden and crisp on most sides, stirring often. This will take from 8 to 10 minutes or so. Remove the tofu to a plate and set aside.
Meanwhile, combine the arrowroot or cornstarch with ¼ cup of the water in a small mixing bowl. Stir until dissolved, then add the remaining sauce ingredients. Stir together and set aside.
Wipe out the pan in which you sautéed the tofu. Add the garlic and just a little water, and cook over low heat for 2 minutes.
Add the broccoli and just enough additional wanter to keep the pan moist; cover and cook over medium-high heat until bright green and tender-crisp, about 3 to 4 minutes.
Stir the tofu and sauce in with the broccoli and cook until the sauce thickens. Taste to see if you’d like more soy sauce.
Garnish with sesame seeds and the optional chili pods or chili flakes, and serve at once on its own or over hot cooked rice.