Creating French Onion Meatballs with Savory Onion Sauce is simple if you follow these steps:

1. Preheat the Oven: Begin by preheating your oven to 400°F (200°C). Line a baking sheet with parchment paper for easy cleanup.

2. Sauté Onions: In a skillet over medium heat, melt 1 tablespoon of butter and add sliced onions. Cook until they start to become soft, about 5 minutes.

3. Add Sugar: Sprinkle in the sugar to help caramelize the onions. Continue cooking, stirring occasionally, until golden brown and soft (about 20 minutes). Set aside to cool.

4. Mix Meatball Ingredients: In a large bowl, combine the ground beef, chopped onion, garlic, breadcrumbs, egg, Worcestershire sauce, thyme, salt, and pepper. Mix until just combined.

5. Form Meatballs: Using your hands, shape the mixture into meatballs, about 1 inch in diameter. Place them on the prepared baking sheet.

6. Bake Meatballs: Bake the meatballs in the preheated oven for 20-25 minutes or until browned and fully cooked.

7. Make Savory Onion Sauce: While the meatballs are baking, heat the remaining tablespoon of butter and olive oil in a large pan. Add the caramelized onions and beef broth, stirring well. Bring to a simmer.

8. Add Cheese: Once the sauce is simmering, stir in the shredded gruyère cheese until melted and combined.

9. Combine Meatballs with Sauce: After the meatballs are cooked, transfer them to the onion sauce and simmer for an additional 5-10 minutes.

10. Garnish and Serve: Finally, sprinkle fresh parsley over the top before serving.

These straightforward steps will guide you in creating French Onion Meatballs with Savory Onion Sauce that is sure to delight everyone at your table.