Add block of tofu to a large plate in between two clean kitchen towels. Add a heavy object such as a large textbook over tofu to squeeze out as much liquid as possible.
Meanwhile, mix all ingredients under stir fry sauce heading together in a small bowl and set aside.
Add all ingredients under rice heading to a rice cooker or pot on the stove and cook until cooked through, about 20 minutes.
Take tofu and cut into 1-inch cubes. Carefully toss with cornstarch in a large bowl, and start heating the canola oil in a large skillet over med-high heat. Add tofu pieces in a large layer, seasoning with salt & pepper. Cook until browned on all sides, about 5 minutes, then remove from heat and transfer to a paper-towel lined plate.
Add a touch more canola oil to the skillet, then stir fry onion, zucchini and red pepper over high heat until veggies are tender, seasoning with salt & pepper. Add tofu back to skillet, then add in sauce and low heat to medium, cooking another 2 minutes until sauce thickens.
Remove from heat, then serve over rice and garnish with green onions and sesame seeds. Serve and enjoy!