Ingredients

For the Meatballs:

• 1 lb ground beef

• 2 tablespoons unsalted butter

• 1⅓ cups finely chopped yellow onion

• 2 teaspoons Worcestershire sauce

• 1 teaspoon granulated sugar

• ⅓ cup beef broth

• 2 teaspoons fresh thyme

• Salt and pepper to taste

For Assembly:

• 4-6 crusty hoagie rolls or 6-inch baguettes

• 2 medium yellow onions, thinly sliced

• 4 tablespoons butter, divided

• 12 slices Swiss cheese or 1 cup grated provolone

• 1-2 cans condensed French onion soup (optional, for extra flavor)

Instructions

Making the Meatballs:

1. Preheat oven to 400°F and spray a baking sheet with non-stick cooking spray.

2. In a medium skillet over medium heat, melt 2 tablespoons butter.

3. Add chopped onions and cook for a few minutes, then add salt, pepper, sugar, Worcestershire sauce, and thyme.

4. Add beef broth and cook until onions are golden brown, adding more broth if needed to prevent burning.

5. In a large bowl, combine ground beef with the caramelized onion mixture using your fingers.

6. Using an ice cream scoop, form approximately 12-16 meatballs and place on the prepared baking sheet.

7. Bake for 12-14 minutes until cooked through.

Preparing the Caramelized Onions:

1. While meatballs bake, melt 2 tablespoons butter in a medium skillet over medium heat.

2. Add sliced onions and cook, stirring frequently to prevent burning, until deeply caramelized (about 15-20 minutes).

3. Remove from heat and set aside.

Assembling the Subs:

1. Slice baguettes in half lengthwise and spread remaining butter on the cut sides.

2. Place on a baking sheet, butter-side up.

3. When meatballs are done, switch oven to broil.

4. Toast the buttered bread under broiler until golden brown, watching closely.

5. Using a slotted spoon, place 3-4 meatballs on the bottom half of each roll.

6. Top generously with caramelized onions and cheese.

7. Return to broiler for 2-3 minutes until cheese is melted and bubbly.