The primary ingredient in a traditional vegetable stir-fry is vegetables, typically a mix that may include bell peppers, broccoli, carrots, snap peas, and bok choy. The vegetables are cut into bite-sized pieces for quick cooking over high heat. Additionally, stir-fries often incorporate sauces, such as soy sauce or teriyaki sauce, to enhance flavor. The preparation emphasizes maintaining the vibrant colors and crisp texture of the vegetables, showcasing their natural freshness. Stir-frying is a quick cooking method that locks in flavors while keeping the vegetables nutritious.