French Onion Soup with Braised Meatballs

Meatballs:

• 1 pound ground beef
• 1 pound ground pork
• ¾ cup heavy cream
• ½ cup grated Parmesan
• ¼ cup panko
• 1 egg
• 2 teaspoons thyme leaves
• 3 ½ teaspoons kosher salt
• 1 teaspoon freshly ground pepper
• Vegetable oil & butter for searing 

Soup:

• 8 tablespoons butter
• 4 onions, thinly sliced
• 1 cup white wine
• 5 garlic cloves, thinly sliced
• 2 tablespoons sherry vinegar
• Kosher salt & pepper
• 2 ½ cups beef broth
• 1 ½ cups coarsely grated Gruyere 

Directions

Make the meatballs:  In bowl of stand mixer add all ingredients through pepper.  Mix until just blended.  Use a cookie scoop of desired size to scoop meatballs out onto cookie sheet. 

In a large oven proof skillet heat add vegetable oil and butter.  Brown the meatballs in several batches so as not to crowd, searing on all sides, turning occasionally.  I cooked these 6 minutes per batch.  Remove to a paper towel covered plate. 

Wipe the pot clean.  Begin the soup by adding butter to the pot over medium low heat.  Add onions, stirring frequently until beginning to brown.  Slowly add wine.  Increase heat to medium-high and cook until onions are fully brown and caramelized, another 15 minutes. 

 Add garlic, sherry vinegar, salt and pepper.  Cook until sherry vinegar is absorbed and garlic is fragrant, about 2 minutes.  Add broth and bring to a boil.  Cover with a lid and transfer to 325 degree oven.  Cook 25 minutes. 

Remove from oven and add meatballs and top with cheese.  Preheat the broiler on high and return pot to oven.  Broil 3 minutes.