Cut tofu in half lengthwise, so you have two thinner rectangles, then wrap in clean kitchen towels. Place on a dinner plate or cutting board. Weigh tofu down with a heavy object like a cast iron skillet, or large pot for at least 20 minutes. Alternatively, use a tofu press.
To a medium bowl, add garlic, ginger, orange juice, orange zest, soy sauce, rice vinegar, coconut sugar and sriracha. Whisk to combine. Add water and cornstarch mixture and whisk until fully combined. Set aside.
Cube the tofu or tear into bite-sized pieces (¾-1 inch). Add tofu, cornstarch, garlic powder, salt and pepper to a large bowl. Toss to coat.
In a large non-stick skillet, heat 1 tbsp oil of choice over medium-high heat. When the pan is hot, add tofu. Cook for 8-10 min, flipping tofu occasionally, until golden-brown and crisp on all sides. Transfer tofu to a plate and set aside.
To the same pan, over medium-high, add broccoli, peppers and 3/4 of the green onion (reserve some for topping). You may have to add another 2 tsp oil here, if there is not enough reserved oil left in the pan. Cook veggies for 4-6 mins, stirring occasionally, until tender-crisp.
Add orange sauce and cook for 1-2 minutes until the sauce begins to thicken. Add the tofu to the pan. Cook for 3-4 mins, until sauce thickens and veggies and tofu are well coated.
Serve over rice. Sprinkle with remaining green onions and toasted sesame seeds.