Making Sweet and Sour Beef Stir-Fry is straightforward. Follow these steps to create a dish that will impress:

1. Prepare the Ingredients: Slice the beef, bell pepper, and onion. Mince the garlic and set aside.
2. Make the Sauce: In a bowl, whisk together soy sauce, rice vinegar, ketchup, brown sugar, cornstarch, and water until smooth. Set aside.
3. Heat the Pan: In a large skillet or wok, heat the vegetable oil over medium-high heat.
4. Cook the Beef: Add the sliced beef to the hot pan. Stir-fry for about 3-4 minutes until browned and cooked through. Remove from the pan and set aside.
5. Stir-Fry the Vegetables: In the same pan, add the bell pepper, onion, and garlic. Stir-fry for about 2-3 minutes until the vegetables are tender-crisp.
6. Add Pineapple: Incorporate the pineapple chunks into the vegetable mixture and stir well.
7. Combine Everything: Return the cooked beef to the pan and pour the sauce over the mixture. Stir well to coat everything evenly.
8. Thicken the Sauce: Cook for an additional 2-3 minutes until the sauce thickens and becomes glossy.
9. Season: Taste and adjust with salt and pepper, if necessary.
10. Serve: Serve hot over cooked rice or noodles.

These simple steps will guide you in creating a delicious Sweet and Sour Beef Stir-Fry that is sure to please!