Prepare the Rice: Start by cooking the white rice according to the package instructions. While the rice is cooking, prepare the tofu stir fry.
Prepare the Tofu: Drain the tofu and pat it dry with paper towels. Cut the tofu into bite-sized cubes.
Cook the Tofu: Heat the vegetable oil in a non-stick skillet or wok over medium-high heat. Add the cubed tofu and cook until golden brown on all sides, about 5-7 minutes. Remove the tofu from the skillet and set it aside.
Cook the Vegetables: In the same skillet, add the bell peppers, broccoli, snap peas, garlic, and ginger. Stir fry the vegetables until they are tender-crisp, about 5 minutes.
Make the Sauce: In a small bowl, whisk together the soy sauce, hoisin sauce, rice vinegar, and sesame oil. If you prefer a thicker sauce, mix the cornstarch with 2 tablespoons of water to create a slurry, then add it to the sauce mixture.
Combine Tofu and Sauce: Return the cooked tofu to the skillet with the vegetables. Pour the sauce over the tofu and vegetables, stirring to combine. Cook for an additional 2-3 minutes, or until the sauce has thickened and everything is well-coated.
Serve: Divide the cooked white rice into bowls and top with the tofu stir fry. Garnish with sesame seeds and sliced green onions.