Meatballs:

• 1 1/2 cups fresh breadcrumbs (or panko breadcrumbs)
• 1/4 cup plus 2 tablespoons whole milk
• 1 1/2 pounds organic ground beef (85/15 ratio)
• 1 tablespoon chopped parsley
• 1 teaspoon fresh thyme leaves, plus extra for garnish
• 1 teaspoon herbes de Provence
• Salt (about 1 teaspoon, or your desired amount)
• Black pepper (about 1/4 teaspoon, or your desired amount)
• 1/2 large white onion, finely minced
• 4 cloves garlic, pressed through garlic press
• 3/4 cup grated Gruyere cheese, divided use
• 1 egg, whisked
• 1 cup shredded whole milk mozzarella cheese
• 4 tablespoons olive oil, divided use

French Onion Sauce:

• 2 tablespoons ghee or butter
• 2 1/2 large white onions, halved and sliced
• Salt
• Black pepper
• 4 cloves garlic, pressed through garlic press
• 1 teaspoon herbes de Provence
• 1 teaspoon dried thyme
• 1/4 cup sherry (or white wine)
• 1 1/2 tablespoons flour
• 2 1/4 cups beef stock
• 2 teaspoons fresh thyme leaves