Creating French Onion Meatballs with Savory Onion Sauce is a straightforward process. Follow these simple steps:

1. Preheat the Oven: Preheat your oven to 400°F (200°C) and line a baking sheet with parchment paper.
2. Mix Meatball Ingredients: In a large bowl, combine the ground beef, ground pork, breadcrumbs, grated Parmesan cheese, finely chopped onion, minced garlic, eggs, Worcestershire sauce, dried thyme, salt, and black pepper. Mix until well blended.
3. Form Meatballs: Shape the mixture into meatballs that are about 1.5 inches in diameter and place them on the prepared baking sheet.
4. Bake Meatballs: Bake the meatballs in the preheated oven for 25-30 minutes, or until they are cooked through and browned.
5. Caramelize Onions: While the meatballs bake, heat olive oil in a large skillet over medium heat. Add the thinly sliced onions and sauté for 10-15 minutes, stirring frequently until they are caramelized and golden brown.
6. Add Broth and Vinegar: Pour the beef broth and balsamic vinegar into the skillet with the caramelized onions. Bring the mixture to a simmer and cook for an additional 5 minutes.
7. Combine Meatballs and Sauce: Once the meatballs are done baking, transfer them to the skillet with the onion sauce. Spoon the sauce over the meatballs and let simmer together for 5 minutes.
8. Garnish: Remove from heat and sprinkle with fresh parsley for a pop of color.

By following these instructions, you’ll have a delicious and fulfilling dish that will impress anyone who dines with you.