Creating sweet and sour meatballs is a simple process that even beginner cooks can master. Follow these steps to prepare this delectable dish:

1. Preheat oven to 400°F (200°C).
2. Prepare the meat mixture:

   • In a bowl, combine the ground meat, breadcrumbs, egg, onion, salt, and pepper.
   • Mix well until all ingredients are thoroughly combined.

3. Shape the meatballs:

   • Roll the mixture into small, even-sized meatballs, ensuring they’re compact to hold their shape during cooking.

4. Bake the meatballs:

   • Place the meatballs on a baking sheet lined with parchment paper.
   • Bake for approximately 20 minutes, or until they are cooked through and golden brown.

5. Prepare the sweet and sour sauce:

   • In a saucepan, combine the ketchup, apple cider vinegar, and brown sugar.
   • Heat the mixture over medium heat until it becomes bubbly, stirring occasionally to prevent sticking.

6. Add the vegetables and fruit:

   • Stir in the pineapple chunks and chopped bell pepper.
   • Allow the sauce to simmer for an additional 5 minutes, enabling the flavors to meld together.

7. Combine meatballs with the sauce:

   • Gently toss the baked meatballs in the prepared sweet and sour sauce, ensuring each meatball is evenly coated.

8. Serve:

   • Serve the sweet and sour meatballs warm, garnished with fresh herbs if desired.