Ingredients
For the Tomato sauce
  • 1/4 cup extra-virgin olive oil
  • 1 large yellow onion, finely chopped
  • 3 garlic cloves, minced
  • 1 28-ounce can crushed tomatoes
  • 1 28-ounce can San Marzano whole plum tomatoes
  • 1/4 cup chopped fresh basil
  • Kosher salt and cracked black pepper
For the Meatballs
  • 3 tablespoons milk
  • 1 large egg, beaten
  • 1/2 cup grated Parmesan cheese, plus more for topping
  • 1/4 cup seasoned breadcrumbs
  • 1 1/2 tablespoons chopped fresh oregano leaves
  • 1 teaspoon kosher salt
  • 1/2 teaspoon cracked black pepper
  • 1 pound ground chicken
  • 4 cups marinara sauce, store bought or homemade (see recipe below)
  • 4 cups parmesan cream sauce (see recipe below)
For the Sandwiches
  • 6 hero rolls, split
  • 6 ounces mozzarella cheese, grated (about 1 1/2 cups)
  • 1/2 cup grated Parmesan cheese
  • 1/2 cup fresh basil, torn
Preparation

For the sauce, in a large saucepan set over medium heat, heat the olive oil. Add the onion and garlic, and cook until soft and starting to brown, 3-5 minutes. Add the tomatoes and their juices, breaking them up with the back of a wooden spoon, and bring to a boil, stirring often. Lower the heat to medium-low and simmer until the sauce has thickened, 15-20 minutes. Stir in the basil and season with salt and pepper.

Meanwhile, in a large bowl, combine the milk, egg, cheese, breadcrumbs, oregano, salt and pepper. Add the ground chicken and mix gently to avoid overworking the meat. Shape into small, golf ball-sized meatballs – You should have 18 to 24 meatballs.

   
Transfer the tomato sauce to a slow cooker and add the meatballs to the sauce. Gently toss to coat before covering. Cook on high for 2 hours or until the meatballs have cooked through.

For the sandwiches, put the rolls on baking sheet, cut side up. Put 3 to 4 meatballs on each roll, spoon some of the sauce over the meatballs, and top with the cheeses.