These sandwiches are great for a group. Make the meatballs ahead of time; when you're ready to serve, the subs come together in minutes.
- 4 tablespoons extra-virgin olive oil divided
- 3 cloves garlic finely chopped
- 1 onion finely chopped
- 1 pound 85 percent lean ground beef
- 1 pound 80 percent lean ground pork
- 3 large eggs lightly beaten
- 1 ½ cups plain bread crumbs
- ½ cup whole milk
- ⅓ cup grated parmesan cheese
- 1 teaspoon dried oregano
- 1 teaspoon kosher salt
- ½ teaspoon freshly ground black pepper
- ¼ teaspoon red pepper flakes
- 6 cups marinara sauce
- 8 to 10 ciabatta rolls for serving
- 16 to 20 slices provolone cheese for serving
- Heat 2 tablespoons olive oil in a medium skillet over medium heat. Add garlic and onion and cook until soft and translucent, 6 to 8 minutes. Set aside to cool. Combine beef, pork, eggs, bread crumbs, milk, parmesan cheese, oregano, salt, pepper, and red pepper flakes in a large bowl. Add cooled onion and garlic mixture and stir until thoroughly incorporated. Shape into meatballs 1 inch in diameter (about the size of a golf ball). You’ll have about 30 meatballs.
- Heat remaining olive oil in a large cast iron skillet over medium-high heat. Cook meatballs in batches until well browned on all sides, about 8 minutes total per batch. Transfer to a large saucepot or Dutch oven set on the stovetop. Pour marinara sauce over meatballs and warm over medium heat. Gently simmer until meatballs have cooked through, about 20 minutes.
- When ready to serve, heat broiler with the top rack positioned about 6 inches away from the heat source. Place ciabatta roll bottoms on a parchment-lined baking sheet. Pile 3 to 4 meatballs onto each sandwich and top with 2 pieces of provolone. Place roll tops, cut side up, on another baking sheet. Broil roll bottoms until bread is toasted and golden at the edges and cheese melts, 1 to 2 minutes. Transfer sandwiches to the bottom rack and put the baking sheet of roll tops under the broiler for 1 to 2 minutes. Remove both baking sheets from the oven, close sandwiches, and serve.