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

1. Preheat the Oven: Set your oven to 400°F (200°C) to prepare for baking the meatballs.

2. Sauté Onions: In a skillet, heat the olive oil over medium heat. Add the finely chopped onion and cook until translucent, about 5 minutes. Then, add the minced garlic and continue cooking for an additional 2 minutes until fragrant.

3. Mix Meatball Ingredients: In a large bowl, combine the ground beef, sautéed onions and garlic, breadcrumbs, egg, 1 cup of shredded Gruyère cheese, fresh parsley, Worcestershire sauce, salt, and pepper. Mix until just combined—be careful not to overmix.

4. Form Meatballs: Using your hands, form the mixture into small meatballs, about 1-1.5 inches in diameter. Place them on a baking sheet lined with parchment paper.

5. Bake Meatballs: Transfer the meatballs to the preheated oven and bake for 20 minutes or until browned and cooked through.

6. Prepare the Savory Sauce: In a saucepan, combine the beef broth, soy sauce, dried thyme, and a pinch of salt and pepper. Bring to a gentle simmer. If you prefer a thicker sauce, whisk in flour gradually until you achieve the desired consistency.

7. Combine and Serve: Once the meatballs are cooked, transfer them to the simmering sauce, gently coating them. For an extra cheesy touch, sprinkle additional Gruyère cheese on top and allow it to melt slightly before serving.