- 2 pounds ground beef (preferably chuck)
- 1/2 cup panko or other breadcrumbs
- 1/2 cup whole milk
- 2 cloves garlic, minced
- Kosher salt and freshly ground pepper
- 3 tablespoons extra-virgin olive oil
- 1/2 onion, diced
- 1 24-ounce jar marinara sauce
- 24 dinner rolls
- 2 cups grated mozzarella cheese
1. Combine the beef, breadcrumbs, milk, garlic, 1/2 teaspoon salt, and pepper to taste in a large bowl and knead the mixture together with your hands. Roll into heaping-tablespoon-size balls.
2. Heat 2 tablespoons olive oil in a large nonstick skillet over medium heat. Add the onion and cook, stirring, until slightly softened, about 2 minutes; remove to a plate. Heat the remaining 1 tablespoon olive oil in the skillet over medium heat. Add the meatballs and cook, turning, until browned all over, about 1 minute. (You might have to do this in 2 batches.)
3. Pour in the marinara sauce and return the onion to the skillet; gently stir. Cover and simmer 20 minutes.
4. When ready to serve, split the dinner rolls and sprinkle some mozzarella on the bottom rolls. Top each with a meatball, some sauce and more mozzarella and sandwich with the top rolls.