Prepare the Tofu: Place a clean kitchen towel or thick paper towel over the tofu and put a heavy object (such as a water-filled jar or a tofu press) on top to drain excess liquid for 15-20 minutes. Then, cut into cubes or rectangles.
Stir Fry the Tofu: In a large skillet or wok, heat sesame oil over medium heat. Add minced garlic and sauté until fragrant. Add tofu cubes and stir fry until golden and crispy. Remove the tofu from the pan and set aside.
Stir Fry the Vegetables: In the same pan, add a bit more oil if needed. Add sliced bell pepper and assorted vegetables. Stir fry until the vegetables are tender yet still crisp.
Prepare the Sauce: In a small bowl, mix soy sauce and sugar until the sugar is dissolved.
Combine Tofu, Vegetables, and Sauce: Return the cooked tofu to the pan. Pour the sauce over the tofu and vegetables. Toss everything together until the tofu and vegetables are evenly coated with the sauce.
Garnish and Serve: Garnish the stir fry with chopped green onions. Serve hot over steamed rice or noodles.