Prepare the Tofu: After pressing the tofu to remove excess moisture, cut it into 1-inch cubes. Sprinkle cornstarch over the tofu cubes and toss gently to coat evenly.
Cook the Tofu: In a large skillet or wok, heat 1 tablespoon of vegetable oil over medium-high heat. Add the cornstarch-coated tofu and fry until golden and crispy on all sides (about 5-7 minutes). Remove the tofu from the skillet and set aside.
Sauté the Vegetables: In the same skillet, add another tablespoon of oil if needed. Add the sliced bell pepper, broccoli florets, and snap peas. Stir-fry for about 3-4 minutes until the vegetables are just tender but still crisp.
Add Aromatics: Add the minced garlic and ginger to the vegetables in the skillet. Stir-fry for about 1 minute until fragrant.
Combine Ingredients: Return the cooked tofu to the skillet with the vegetables. Pour in the sweet chili sauce, soy sauce, and rice vinegar. Toss everything together gently to ensure the tofu and veggies are well coated in the sauce.
Season and Serve: Season with salt and pepper to taste. Continue to cook for an additional 2 minutes, allowing the sauce to thicken slightly.
Garnish and Enjoy: Remove the stir-fry from heat and garnish with chopped green onions and sesame seeds before serving.